Combined capacitive sensing

ABSTRACT

A processing system comprises a sensor module and a determination module. The sensor module comprises sensing circuitry coupled to sensor electrodes of a sensor electrode pattern. The sensor module is configured to: drive a modulated signal onto a first sensor electrode of the sensor electrode pattern; receive first resulting signals from the first sensor electrode; and receive second resulting signals from a second sensor electrode of the sensor electrode pattern. The second resulting signals comprise effects corresponding to the modulated signal, and the first resulting signals and the second resulting signals are simultaneously received. The determination module configured to determine a change in capacitive coupling between an input object and the first sensor electrode based on the first resulting signals and a change in capacitive coupling between the first and second sensor electrodes based on the second resulting signals.

CROSS REFERENCE TO RELATED APPLICATIONS (PROVISIONAL)

This application claims priority to and benefit of co-pending U.S.Provisional Patent Application No. 61/953,671 filed on Mar. 14, 2014entitled “Combined Capacitive Sensing” by Joseph Kurth Reynolds et al.,having Attorney Docket No. SYNA-20121114-01.PRO, and assigned to theassignee of the present application, the disclosure of which is herebyincorporated herein by reference in its entirety.

BACKGROUND

Input devices including proximity sensor devices (also commonly calledtouchpads or touch sensor devices) are widely used in a variety ofelectronic systems. A proximity sensor device typically includes asensing region, often demarked by a surface, in which the proximitysensor device determines the presence, location and/or motion of one ormore input objects. Proximity sensor devices may be used to provideinterfaces for the electronic system. For example, proximity sensordevices are often used as input devices for larger computing systems(such as opaque touchpads integrated in, or peripheral to, notebook ordesktop computers). Proximity sensor devices are also often used insmaller computing systems (such as touch screens integrated in cellularphones and tablet computers). Such touch screen input devices aretypically superimposed upon or otherwise collocated with a display ofthe electronic system.

SUMMARY

In a processing system embodiment, the processing system comprises asensor module and a determination module. The sensor module comprisessensing circuitry coupled to sensor electrodes of a sensor electrodepattern. The sensor module is configured to: drive a modulated signalonto a first sensor electrode of the sensor electrode pattern; receivefirst resulting signals from the first sensor electrode; and receivesecond resulting signals from a second sensor electrode of the sensorelectrode pattern. The second resulting signals comprise effectscorresponding to the modulated signal, and the first resulting signalsand the second resulting signals are simultaneously received. Thedetermination module configured to determine a change in capacitivecoupling between an input object and the first sensor electrode based onthe first resulting signals and a change in capacitive coupling betweenthe first and second sensor electrodes based on the second resultingsignals.

BRIEF DESCRIPTION OF DRAWINGS

The drawings referred to in this Brief Description of Drawings shouldnot be understood as being drawn to scale unless specifically noted. Theaccompanying drawings, which are incorporated in and form a part of theDescription of Embodiments, illustrate various embodiments and, togetherwith the Description of Embodiments, serve to explain principlesdiscussed below, where like designations denote like elements.

FIG. 1 is a block diagram of an example input device, in accordance withembodiments.

FIG. 2A shows a portion of an example sensor electrode pattern which maybe utilized in a sensor to generate all or part of the sensing region ofan input device, such as a touch screen, according to some embodiments.

FIG. 2B illustrates an example matrix array of sensor electrodes,according to various embodiments.

FIG. 3A shows more detailed block diagram of an the input device of FIG.1, according to an embodiment.

FIG. 3B shows an exploded side sectional view of a portion of the inputdevice of FIG. 3A, according to an embodiment.

FIG. 4 shows a matrix of capacitances associated with the input deviceillustrated in FIGS. 3A and 3B, according to an embodiment.

FIG. 5 shows a block diagram of an example processing system, accordingto an embodiment.

FIG. 6A shows an exploded front side elevation of the example sensorelectrode pattern of FIG. 2A with labeled capacitances, according to anembodiment.

FIG. 6B shows an exploded left side elevation of the example sensorelectrode pattern of FIG. 2A with labeled capacitances, according to anembodiment.

FIG. 6C shows an exploded front side elevation of the example sensorelectrode pattern of FIG. 2A with labeled capacitances, according to anembodiment.

FIG. 6D shows an exploded left side elevation of the example sensorelectrode pattern of FIG. 2A with labeled capacitances, according to anembodiment.

FIGS. 7A-7G show a flow diagram of an example method of capacitivesensing, according to various embodiments.

DESCRIPTION OF EMBODIMENTS

The following Description of Embodiments is merely provided by way ofexample and not of limitation. Furthermore, there is no intention to bebound by any expressed or implied theory presented in the precedingBackground, Summary, or Brief Description of Drawings or the followingDescription of Embodiments.

Overview of Discussion

Herein, various embodiments are described that provide input devices,processing systems, and methods that facilitate improved usability. Invarious embodiments described herein, the input device may be acapacitive sensing input device. In general, conventional capacitancesensing measures substantially one type of capacitance at a time withsensor electrodes of a sensor electrode pattern; typically either anabsolute capacitance associated with a sensor electrode or atranscapacitance measured between two non-parallel sensor electrodes.For example, conventionally a capacitive touch implementation mayinadvertently measure some aspects of both absolute capacitance andtranscapacitance at a point in time when attempting to measure onlyabsolute capacitance or only transcpacitnace. Not only are theseconventional measurements inadvertent, but they are also not made in away that they can be independently combined and the effects of eachseparated for reporting. Herein, systems, methods, and techniques forperforming combined capacitive sensing, are disclosed. In general,combined capacitive sensing, as described herein, involves using asensor electrode pattern to make numerous different types of capacitivemeasurements simultaneously (e.g., simultaneous measurement of absolutecapacitance and one or more types of transcapacitance) such that theeffect of user input on the different types of measurements may be usedto determine a reported position of an input object or user interfaceresponse in response to user input.

Discussion begins with a description of an example input device withwhich or upon which various embodiments described herein may beimplemented. An example sensor electrode pattern is then described. Ageneral description of techniques for combined capacitive sensing with asensor electrode pattern is provided along with some examples. This isfollowed by description of an example processing system and somecomponents thereof which may be utilized for combined capacitivesensing. The processing system may be utilized with or as a portion ofan input device, such as a capacitive sensing input device. Some morespecific examples of combined capacitive sensing are illustrated anddescribed in conjunction with an example sensor electrode pattern.Operation of the example input devices, processing system, andcomponents thereof are then further described in conjunction withdescription of an example method of combined capacitive sensing.

Example Input Device

Turning now to the figures, FIG. 1 is a block diagram of an exemplaryinput device 100, in accordance with various embodiments. Input device100 may be configured to provide input to an electronic system/device150. As used in this document, the term “electronic system” (or“electronic device”) broadly refers to any system capable ofelectronically processing information. Some non-limiting examples ofelectronic systems include personal computers of all sizes and shapes,such as desktop computers, laptop computers, netbook computers, tablets,web browsers, e-book readers, and personal digital assistants (PDAs).Additional example electronic systems include composite input devices,such as physical keyboards that include input device 100 and separatejoysticks or key switches. Further example electronic systems includeperipherals such as data input devices (including remote controls andmice), and data output devices (including display screens and printers).Other examples include remote terminals, kiosks, and video game machines(e.g., video game consoles, portable gaming devices, and the like).Other examples include communication devices (including cellular phones,such as smart phones), and media devices (including recorders, editors,and players such as televisions, set-top boxes, music players, digitalphoto frames, and digital cameras). Additionally, the electronic systemscould be a host or a slave to the input device.

Input device 100 can be implemented as a physical part of an electronicsystem 150, or can be physically separate from electronic system 150. Asappropriate, input device 100 may communicate with parts of theelectronic system using any one or more of the following: buses,networks, and other wired or wireless interconnections. Examplesinclude, but are not limited to: Inter-Integrated Circuit (I2C), SerialPeripheral Interface (SPI), Personal System 2 (PS/2), Universal SerialBus (USB), Bluetooth®, Radio Frequency (RF), and Infrared DataAssociation (IrDA).

In FIG. 1, input device 100 is shown as a proximity sensor device (alsooften referred to as a “touchpad” or a “touch sensor device”) configuredto sense input provided by one or more input objects 140 in a sensingregion 120. Example input objects include fingers and styli (passive andactive), as shown in FIG. 1.

Sensing region 120 encompasses any space above, around, in and/or nearinput device 100, in which input device 100 is able to detect user input(e.g., user input provided by one or more input objects 140). The sizes,shapes, and locations of particular sensing regions may vary widely fromembodiment to embodiment. In some embodiments, sensing region 120extends from a surface of input device 100 in one or more directionsinto space until signal-to-noise ratios prevent sufficiently accurateobject detection. The distance to which this sensing region 120 extendsin a particular direction, in various embodiments, may be on the orderof less than a millimeter, millimeters, centimeters, or more, and mayvary significantly with the type of sensing technology used and theaccuracy desired. Thus, some embodiments sense input that comprises nocontact with any surfaces of input device 100, contact with an inputsurface (e.g., a touch surface) of input device 100, contact with aninput surface of input device 100 coupled with some amount of appliedforce or pressure, and/or a combination thereof. In various embodiments,input surfaces may be provided by surfaces of casings within which thesensor electrodes reside, by face sheets applied over the sensorelectrodes or any casings, transparent lenses over a touch screendisplay, etc. In some embodiments, sensing region 120 has a rectangularshape when projected on to an input surface of input device 100.

Input device 100 may utilize any combination of sensor components andsensing technologies to detect user input in sensing region 120. Inputdevice 100 comprises one or more sensing elements for detecting userinput. As a non-limiting example, input device 100 may use capacitivetechniques.

Some implementations are configured to provide images that span one,two, three, or higher dimensional spaces. Some implementations areconfigured to provide projections of input along particular axes orplanes.

In some capacitive implementations of input device 100, voltage orcurrent is applied to create an electric field. Nearby input objectscause changes in the electric field, and produce detectable changes incapacitive coupling that may be detected as changes in voltage, current,or the like.

Some capacitive implementations utilize arrays or other regular orirregular patterns of capacitive sensing elements to create electricfields. In some capacitive implementations, separate sensing elementsmay be ohmically shorted together to form larger sensor electrodes. Somecapacitive implementations utilize resistive sheets, which may beuniformly resistive.

Some capacitive implementations utilize “self capacitance” (or “absolutecapacitance”) sensing methods based on changes in the capacitivecoupling between sensor electrodes and an input object. In variousembodiments, an input object near the sensor electrodes alters theelectric field near the sensor electrodes, thus changing the measuredcapacitive coupling. In one implementation, an absolute capacitancesensing method operates by modulating sensor electrodes with respect toa reference voltage (e.g., system ground), and by detecting thecapacitive coupling between the sensor electrodes and input objects. Inone embodiment, the capacitive coupling between the sensor electrodesand input objects may be combined with the effects of the input oncoupling between sensor electrodes to estimate the total coupling of theuser to the reference voltage and/or to estimate low ground mass (LGM).

Some capacitive implementations utilize “mutual capacitance” (alsoreferred to herein as “transcapacitance”) sensing methods based onchanges in the capacitive coupling between sensor electrodes. In variousembodiments, an input object near the sensor electrodes alters theelectric field between the sensor electrodes, thus changing the measuredcapacitive coupling. In one implementation, a transcapacitive sensingmethod operates by detecting the capacitive coupling between one or moretransmitter sensor electrodes (also “transmitter electrodes” or“transmitters”) and one or more receiver sensor electrodes (also“receiver electrodes” or “receivers”). In some embodiments, atranscapacitance is measured between a transmitter electrode and areceiver that cross one another. In some embodiments, a transcapacitivemeasurement is made between a transmitter electrode and a receiverelectrode which do not cross one another. Collectively transmitters andreceivers may be referred to as sensor electrodes or sensor elements.Transmitter sensor electrodes may be modulated relative to a referencevoltage (e.g., system ground, a stationary voltage potential, or amodulated voltage signal) to transmit transmitter signals. Receiversensor electrodes may be coupled with the reference voltage tofacilitate receipt of resulting signals. A resulting signal may compriseeffect(s) corresponding to one or more transmitter signals, and/or toone or more sources of environmental interference (e.g., activelymodulated pen or other electromagnetic signals). Sensor electrodes maybe dedicated transmitters or receivers, or may be configured to bothtransmit and receive. In some embodiments, one or more receiverelectrodes may be operated to receive a resulting signal when notransmitter electrodes are transmitting (e.g., the transmitters aredisabled). In this manner, the resulting signal represents noisedetected in the operating environment of sensing region 120.

In FIG. 1, a processing system 110 is shown as part of input device 100.Processing system 110 is configured to operate the hardware of inputdevice 100 to detect input in sensing region 120. Processing system 110comprises parts of or all of one or more integrated circuits (ICs)and/or other circuitry components. For example, a processing system formay comprise transmitter circuitry configured to transmit signals withtransmitter sensor electrodes, and/or receiver circuitry configured toreceive signals with receiver sensor electrodes. Such transmittercircuitry may include one or more analog components such as amplifiers(e.g., buffers) which are used to drive transmitter signals onto sensorelectrodes. Such receiver circuitry may include one or more analogcomponents such as amplifiers which are used to receive and amplifysignals from the sensor electrodes. In some embodiments, some analogcomponents are shared between transmitter circuitry and receivercircuitry. In various embodiments, one or more analog components of thetransmitter and/or receiver circuitry may be used for bothtranscapacitive and absolute capacitive sensing. In some embodiments,processing system 110 also comprises electronically-readableinstructions, such as firmware code, software code, and/or the like. Insome embodiments, components composing processing system 110 are locatedtogether, such as near sensing element(s) of input device 100. In otherembodiments, components of processing system 110 are physically separatewith one or more components close to sensing element(s) of input device100, and one or more components elsewhere. For example, input device 100may be a peripheral coupled to a desktop computer, and processing system110 may comprise software configured to run on a central processing unitof the desktop computer and one or more ICs (perhaps with associatedfirmware) separate from the central processing unit. As another example,input device 100 may be physically integrated in a phone, and processingsystem 110 may comprise circuits and firmware that are part of a mainprocessor of the phone. In some embodiments, processing system 110 isdedicated to implementing input device 100. In other embodiments,processing system 110 also performs other functions, such as operatingdisplay screens, containing a display buffer driving haptic actuators,etc.

Processing system 110 may be implemented as a set of modules that handledifferent functions of processing system 110. Each module may comprisecircuitry that is a part of processing system 110, firmware, software,or a combination thereof. In various embodiments, different combinationsof modules may be used. Example modules include hardware operationmodules for operating hardware such as sensor electrodes and displayscreens, data processing modules for processing data such as sensorsignals and positional information, and reporting modules for reportinginformation. Further example modules include sensor modules configuredto operate sensing element(s) to detect input, determination modulesconfigured to determine absolute capacitance and positions of any inputsobjects therefrom, determination modules configured to determine changesin transcapacitance and positions of any input objects therefrom, tocombine changes in transcapacitance and absolute capacitance todetermine positions of any input objects therefrom, and/or to determineinterference or actively modulated user inputs and determine their userinput state (e.g., excessive noise, hover, contact force, button pressetc.), identification modules configured to identify gestures such asmode changing gestures, and mode changing modules for changing operationmodes.

In some embodiments, processing system 110 responds to user input (orlack of user input) in sensing region 120 directly by causing one ormore actions. Example actions include changing operation modes, as wellas GUI actions such as cursor movement, selection, menu navigation, andother functions. In some embodiments, processing system 110 providesinformation about the input (or lack of input) to some part of theelectronic system (e.g., to a central processing system of theelectronic system that is separate from processing system 110, if such aseparate central processing system exists). In some embodiments, somepart of the electronic system processes information received fromprocessing system 110 to act on user input, such as to facilitate a fullrange of actions, including mode changing actions and GUI actions.

For example, in some embodiments, processing system 110 operates thesensing element(s) of input device 100 to produce electrical signalsindicative of input (or lack of input) in sensing region 120. Processingsystem 110 may perform any appropriate amount of processing on theelectrical signals in producing the information provided to theelectronic system. For example, processing system 110 may digitizeanalog electrical signals obtained from the sensor electrodes. Asanother example, processing system 110 may perform filtering or othersignal conditioning. As yet another example, processing system 110 maysubtract or otherwise account for a baseline, such that the informationreflects a difference between the electrical signals and the baseline.As yet further examples, processing system 110 may determine positionalinformation, recognize inputs as commands, recognize handwriting, andthe like.

“Positional information” as used herein broadly encompasses absoluteposition, relative position, velocity, acceleration, and other types ofspatial information. Exemplary “zero-dimensional” positional informationincludes near/far or contact/no contact information. Exemplary“one-dimensional” positional information includes positions along anaxis. Exemplary “two-dimensional” positional information includesmotions in a plane. Exemplary “three-dimensional” positional informationincludes instantaneous or average velocities in space. Further examplesinclude other representations of spatial information. Historical dataregarding one or more types of positional information may also bedetermined and/or stored, including, for example, historical data thattracks position, motion, or instantaneous velocity over time.

In some embodiments, input device 100 is implemented with additionalinput components that are operated by processing system 110 or by someother processing system. These additional input components may provideredundant functionality for input in sensing region 120, or some otherfunctionality. FIG. 1 shows buttons 130 near sensing region 120 that canbe used to facilitate selection of items using input device 100. Othertypes of additional input components include sliders, balls, wheels,switches, and the like. Conversely, in some embodiments, input device100 may be implemented with no other input components.

In some embodiments, input device 100 may be a touch screen, and sensingregion 120 overlaps at least part of an active area of a display screen.For example, input device 100 may comprise substantially transparent(including but not limited to opaque metal meshes) sensor electrodesoverlaying the display screen and provide a touch screen interface forthe associated electronic system 150. The display screen may be any typeof dynamic display capable of displaying a visual interface to a user,and may include any type of light emitting diode (LED), organic LED(OLED), cathode ray tube (CRT), liquid crystal display (LCD), plasma,electroluminescence (EL), or other display technology. Input device 100and the display screen may share physical elements. For example, someembodiments may utilize some of the same electrical components fordisplaying and sensing. As another example, the display screen may beoperated in part or in total by processing system 110.

It should be understood that while many embodiments are described in thecontext of a fully functioning apparatus, the mechanisms are capable ofbeing distributed as a program product (e.g., software) in a variety offorms. For example, the mechanisms that are described may be implementedand distributed as a software program on information bearing media thatare readable by electronic processors (e.g., non-transitorycomputer-readable and/or recordable/writable information bearing mediareadable by processing system 110). Additionally, the embodiments applyequally regardless of the particular type of medium used to carry outthe distribution. Examples of non-transitory, electronically readablemedia include various discs, memory sticks, memory cards, memorymodules, and the like. Electronically readable media may be based onflash, optical, magnetic, holographic, or any other tangible storagetechnology.

FIG. 2A shows a portion of an example sensor electrode pattern 200 whichmay be utilized in a sensor to generate all or part of the sensingregion of input device 100, according to various embodiments. Inputdevice 100 is configured as a capacitive sensing input device whenutilized with a capacitive sensor electrode pattern. For purposes ofclarity of illustration and description, a non-limiting simplerectangular sensor electrode pattern 200 with a first plurality ofsensor electrodes X and a second plurality of sensor electrodes Y isillustrated. Although the labels X and Y are utilized and FIG. 2Aillustrates that the X and Y sensor electrode subsets are substantiallyorthogonal to one another, an orthogonal relationship between thecrossing first and second subsets of sensor electrodes is not required.In one embodiment, the sensor electrodes X and Y may be arranged ondifferent sides of the same substrate. For example, each of the firstplurality X and second plurality of sensor electrode may be disposed onone of the surfaces of a substrate. In one such an embodiment, sensorelectrodes X are disposed on a first side of a substrate, while sensorelectrodes Y are disposed on an opposing side of the substrate. In otherembodiments, the sensor electrodes may be arranged on differentsubstrates. For example, each of the each of the first and secondplurality of sensor electrode(s) may be disposed on surfaces of separatesubstrates which may be adhered together. In another embodiment, thesensor electrodes are all located on the same side or surface of acommon substrate. In one example, a first plurality of the sensorelectrodes comprise jumpers in regions where the first plurality ofsensor electrodes crossover the second plurality of sensor electrodes,where the jumpers are insulated from the second plurality of sensorelectrodes. In one or more embodiments, the sensor electrodes maycomprise at least one display electrode configured for display updatingand capacitive sensing. The display electrode may be selected from alist comprising, but not limited to, a segment of a segmented Vcomelectrode, a source electrode, a gate electrode, a cathode electrode,and an anode electrode.

The first plurality of sensor electrodes may extend in a firstdirection, and the second plurality of sensor electrodes may extend in asecond direction. The second direction may be similar to or differentfrom the first direction. For example, the second direction may beparallel with, perpendicular to, or diagonal to the first direction.Further, the sensor electrodes may each have the same size or shape ordiffering size and shapes. In one embodiment, the first plurality ofsensor electrodes may be larger (larger surface area) than the secondplurality of sensor electrodes. In other embodiments, the firstplurality and second plurality of sensor electrodes may have a similarsize and/or shape. Thus, the size and/or shape of the one or more of thesensor electrodes may be different than the size and/or shape of anotherone or more of the sensor electrodes. Nonetheless, each of the sensorelectrodes may be formed into any desired shape on their respectivesubstrates.

In other embodiments, one or more of sensor electrodes are disposed onthe same side or surface of the common substrate and are isolated fromeach other in the sensing region 120.

FIG. 2B illustrates an example matrix array of sensor electrodes,according to various embodiments. As illustrated in FIG. 2B, the sensorelectrodes 210 may be disposed in a matrix array where each sensorelectrode may be referred to as a matrix sensor electrode. In oneembodiment, each sensor electrode of sensor electrodes is substantiallysimilar size and/or shape. In one embodiment, one or more of sensorelectrodes of the matrix array of sensor electrodes may vary in at leastone of size and shape. Each sensor electrode of the matrix array maycorrespond to a pixel of a capacitive image. Further, two or more sensorelectrodes of the matrix array may correspond to a pixel of a capacitiveimage. In various embodiments, each sensor electrode of the matrix arraymay be coupled a separate capacitive routing trace of a plurality ofcapacitive routing traces. In various embodiments, the sensor electrodes210 comprises one or more gird electrodes disposed between at least twosensor electrodes of sensor electrodes. The grid electrode and at leastone sensor electrode may be disposed on a common side of a substrate,different sides of a common substrate and/or on different substrates. Inone or more embodiments, the sensor electrodes and the grid electrode(s)may encompass an entire voltage electrode of a display device. Thevoltage electrode may be selected from a list comprising, but notlimited to, a Vcom electrode, a segment of a segmented Vcom electrode, asource electrode, a gate electrode, a cathode electrode, and an anodeelectrode. Although the sensor electrodes may be electrically isolatedon the substrate, the electrodes may be coupled together outside of thesensing region 120—e.g., in a connection region. In one embodiment, afloating electrode may be disposed between the grid electrode and thesensor electrodes. In one particular embodiment, the floating electrode,the grid electrode and the sensor electrode comprise the entirety of acommon electrode of a display device. Each sensor electrode may beindividually coupled to the processing system or coupled to theprocessing system through one or more multiplexers or switchingmechanisms.

The illustrated sensor electrode pattern in FIG. 2A is made up of aplurality of sensor electrodes X (X1, X2, X3, X4) which may be used asboth transmitter electrodes and receiver electrodes and a plurality ofsensor electrodes Y (Y1, Y2, Y3, Y5) which may be used as bothtransmitter electrodes and receiver electrodes. Sensor electrodes X andY overlay one another in an orthogonal arrangement, in this example. Itis appreciated that in a crossing sensor electrode pattern, such as theillustrated example of FIG. 2A, some form of insulating material orsubstrate is typically disposed between sensor electrodes Y and X. Forpurposes of clarity, depictions of these substrates and insulators havebeen omitted herein.

In the illustrated example of FIG. 2A, capacitive pixels may be measuredvia transcapacitive sensing. For example, capacitive pixels may belocated at regions where transmitter and receiver electrodes interact.The pixels may have a variety of shapes, depending on the nature of theinteraction. In the illustrated example, capacitive pixels are locatedwhere transmitter and receiver electrodes overlap one another.Capacitive coupling 290 illustrates one of the capacitive couplingsgenerated by sensor electrode pattern 200 during transcapacitive sensingwith sensor electrode Y5 as a transmitter electrode and sensor electrodeX4 as a receiver electrode or with sensor electrode X4 as a transmitterelectrode and sensor electrode Y5 as a receiver electrode. Capacitivecoupling 295 illustrates one of the capacitive couplings generated bysensor electrode pattern 200 during transcapacitive sensing with sensorelectrode Y5 as a transmitter electrode and sensor electrode Y4 as areceiver electrode or with sensor electrode Y4 as a transmitterelectrode and sensor electrode Y5 as a receiver electrode. Capacitivecoupling 297 illustrates one of the capacitive couplings generated bysensor electrode pattern 200 during transcapacitive sensing with sensorelectrode X4 as a transmitter electrode and sensor electrode Y3 as areceiver electrode or with sensor electrode X3 as a transmitterelectrode and sensor electrode X4 as a receiver electrode. Whenaccomplishing transcapacitive measurements, the capacitive couplings,are areas of localized capacitive coupling between sensor electrodes.The capacitive coupling between sensor electrodes change with theproximity and motion of input objects in the sensing region associatedwith sensor electrodes. In some instances, areas of capacitive couplingsuch as 290, 295, and 297 may be referred to as capacitive pixels. Itshould be noted that the different types of capacitive couplings 290,295, 297 have different shapes, sizes, and or orientations from oneanother due to the particular nature of the interactions. As anotherexample, absolute capacitive couplings may increase where the area ofoverlap between a sensor electrode and a user input depending on theseries coupling of the user through a voltage reference (e.g., systemground) from which the respective receiver is modulated. As one example,dashed box 299 represents an area of absolute capacitive coupling whichmay be associated with sensor electrode X1; other sensor electrodessimilar have areas of absolute capacitive coupling. As a furtherexample, the absolute capacitive series couplings may also include theeffect of user coupling to other transmitter electrodes in parallel tothe coupling to the reference voltage.

In the illustrated example of FIG. 2B, capacitive pixels may be measuredvia transcapacitive sensing. For example, capacitive pixels may belocated at regions where transmitter and receiver electrodes interact.In the illustrated example, capacitive pixels are located wheretransmitter and receiver electrodes are coupled to one another. Forexample, capacitive coupling 280 illustrates one of the capacitivecouplings generated by sensor electrode pattern 210 duringtranscapacitive sensing with sensor electrode SE1 as a transmitterelectrode and sensor electrode SE2 as a receiver electrode or withsensor electrode SE1 as a transmitter electrode and sensor electrode SE2as a receiver electrode. Capacitive coupling 281 illustrates one of thecapacitive couplings generated by sensor electrode pattern 210 duringtranscapacitive sensing with sensor electrode SE1 as a transmitterelectrode and sensor electrode SE3 as a receiver electrode or withsensor electrode SE3 as a transmitter electrode and sensor electrode SE1as a receiver electrode. Capacitive coupling 282 illustrates one of thecapacitive couplings generated by sensor electrode pattern 210 duringtranscapacitive sensing with sensor electrode SE1 as a transmitterelectrode and sensor electrode SE4 as a receiver electrode or withsensor electrode SE4 as a transmitter electrode and sensor electrode SE1as a receiver electrode. When accomplishing transcapacitivemeasurements, the capacitive couplings, are areas of localizedcapacitive coupling between sensor electrodes. The capacitive couplingbetween sensor electrodes changes with the proximity and motion of inputobjects in the sensing region associated with sensor electrodes. As oneexample, dashed box 284 represents an area of absolute capacitivecoupling which may be associated with sensor electrode SE4; other sensorelectrodes in sensor electrode pattern 210 similar have areas ofabsolute capacitive coupling. The absolute capacitance of any one ormore of the sensor electrodes in sensor electrode pattern 210 may alsobe measured. For purposes of brevity and clarity, the embodimentsdiscussed in FIGS. 3A-7G are described using the example sensorelectrode pattern 200 of FIG. 2A. It should be appreciated by one ofskill in the art that the embodiments described in FIGS. 3A-7G cansimilarly be implemented using a variety of other sensor electrodepatterns, including sensor electrode pattern 210 of FIG. 2B.

In some embodiments, sensor electrode pattern 200 is “scanned” todetermine these capacitive couplings. That is, the transmitterelectrodes are driven to transmit transmitter signals. Transmitters maybe operated such that one transmitter electrode transmits at one time,or multiple transmitter electrodes transmit at the same time. Wheremultiple transmitter electrodes transmit simultaneously, these multipletransmitter electrodes may transmit the same transmitter signal andproduce an effectively larger transmitter electrode, or these multipletransmitter electrodes may transmit different transmitter signals. Forexample, multiple transmitter electrodes may transmit differenttransmitter signals according to one or more coding schemes that enabletheir combined effects on the resulting signals of receiver electrodesto be independently determined based on the multiple results of multipleindependent codes. In one embodiment, a first sensor electrode may bedriven with a first transmitter signal based on a first code of aplurality of distinct digital codes and a second sensor electrode may bedriven with a second transmitter signal based on a second code of theplurality of distinct digital codes, where the first code may beorthogonal to the second code. With regard to FIG. 2B, the sensorelectrodes may be driven and received with such that at least two sensorelectrodes may be simultaneously driven. In one or more embodiments,each of the sensor electrodes may be simultaneously driven. In such anembodiment, each sensor electrode may be driven with a transmittersignal based on a different one of a plurality of orthogonal digitalcodes. Further, the sensor electrodes may be driven such that a first atleast one sensor electrode is driven differently that a second at leastsensor electrode. In one or more embodiments, the sensor electrodes aredriven such that along each row and column alternating sensor electrodesare driven differently.

The receiver electrodes may be operated singly or in multiples toacquire resulting signals. The resulting signals may be used todetermine measurements of the capacitive couplings at the capacitivepixels. Note that the receiver signals may also be multiplexed such thatmultiple electrodes may be measured with a single receiver (e.g., analogfront end or “AFE”). Furthermore, the receiver multiplexer may beimplemented such that the receiver is simultaneously coupled to andsimultaneously receives resulting signals from multiple sensorelectrodes. In such implementations, the resulting signals comprisecoded results from the multiple sensor electrodes. Note in variousembodiments, that multiple “absolute capacitance” electrodes may bedriven simultaneously with the same modulation relative to a referencevoltage and such that they are guarding each other, or some may bedriven relative to each other modulated relative to a system referencevoltage such that they measure both a transcapacitive and an absolutecapacitive signal simultaneously.

A set of measurements from the capacitive couplings or pixels form a“capacitive image” (also “capacitive frame”) representative of thetranscapacitive couplings a. For example a capacitive image may be madeup of a set of capacitive pixels, such as capacitive coupling 290.Multiple capacitive images may be acquired over multiple time periods,and differences between them used to derive information about input inthe sensing region. For example, successive capacitive images acquiredover successive periods of time can be used to track the motion(s) ofone or more input objects entering, exiting, and within the sensingregion. Also, in various embodiments, a “capacitive image” may be formedby absolute capacitive measurements of a matrix array of sensorelectrodes (e.g., sensor electrode pattern 210 of FIG. 2B). In suchembodiments, sensor electrodes may be operated for absolute capacitivesensing depending on the multiplexer settings. For example the sensorelectrodes may be grouped in to rows, columns and/or other combinationsof sensor electrodes.

A set of measurements from the capacitive coupling/pixels along one axismay be taken to form a “transcapacitive profile” (also “profile frame”)representative of the capacitive couplings at the capacitivecouplings/pixels between parallel electrodes on an axis (e.g.,electrodes X or Y). For example a transcapacitive profile may be made upfrom a set of horizontal capacitive pixels, such as capacitivecoupling/pixel 295, or from a set of vertical pixels, such as capacitivecoupling/pixel 297. Multiple transcapacitive profiles along one or moreaxes may be acquired over multiple time periods, and differences betweenthem used to derive information about input in the sensing region. Forexample, successive transcapacitive profiles acquired over successiveperiods of time for an axis can be used to track the motion(s) of one ormore input objects entering, exiting, and within the sensing region.Alternately, a set of measurements from the capacitive coupling along anaxis may be taken from an “absolute capacitive profile” representativeof the capacitive couplings between the parallel electrodes on an axisand the series capacitance from the user input through the coupling tothe reference electrode which the absolute receivers are modulated.

In some embodiments, one or more sensor electrodes Y or X may beoperated to perform absolute capacitive sensing at a particular instanceof time. For example, sensor electrode X1 may be charged by driving amodulated signal onto sensor electrode X1, and then the capacitance ofreceiver electrode X1 to system reference voltage including the couplingthrough the user input may be measured. In such an embodiment, an inputobject 140 interacting with sensor electrode X1 alters the electricfield near sensor electrode X1, thus changing the measured capacitivecoupling. In this same manner, a plurality of sensor electrodes X and/orsensor electrodes Y may be used to measure absolute capacitance atdifferent times or at times that overlap partially or completely.

As will be described herein, in some embodiments, combined sensing canbe performed by driving a sensing signal onto a sensor electrode (e.g.,sensor electrode X1) for the purposes of measuring absolute capacitancewith that sensor electrode and, simultaneously with the driving of thatsensor electrode, other sensor electrodes that cross and do not crossthat sensor electrode (e.g., sensor electrodes Y that cross sensorelectrode X1 and one or more other sensor electrodes X which do notcross sensor electrode X1) may be used as receivers to obtaintranscapacitive measurements between themselves and the driven sensorelectrode.

FIG. 3A shows a more detailed block diagram of the input device 100 ofFIG. 1, according to an embodiment. By way of example and not oflimitation, FIG. 3A depicts and describes a crossing sensor electrodepattern as shown in FIG. 2A; however, it should be appreciated that thedescription and techniques presented with respect to FIG. 3A maysimilarly be applied to the sensor electrode pattern 210 of FIG. 2B. InFIG. 3A capacitive sensing input device 100, in the illustratedembodiment, includes sensor electrodes of sensor electrode pattern 200.It should be appreciated that for purposes of clarity some componentssuch as substrates, insulating material, and routing traces are omittedso as not to obscure the depicted portions. Sensor electrodes X and Y orsensor electrode pattern 200 are shown coupled by routing traces toprocessing system 110. For example, routing traces 310 couple sensorelectrodes Y1, Y2, Y3, Y4, and Y5 with processing system 110, androuting traces 320 couple sensor electrodes X1, X2, X3, and X4 withprocessing system 110. Sensor electrode pattern 200 is disposed above aconductive system electrode G. The system electrode may be driven with asystem reference, which may also be referred to as a system ground. Inone or more embodiments, the system electrode G may be part of thehousing of the input device, or the battery of the input device. In oneor more embodiments an optional electrode B (depicted in FIG. 3B but notin FIG. 3A) may be disposed between the sensor electrodes and systemground electrode. Electrode B may be driven with a shielding signal,which may be a substantially constant voltage or a varying voltage(i.e., guard signal).

Electrode S1 overlaps at least a portion of routing traces 310, and maybe used to shield signals on these routing traces. Electrode S1 iscoupled with processing system 110 by routing trace 311 and may be heldat a constant voltage potential or modulated by processing system 110.An electrode S2 overlaps at least a portion of routing traces 320, andmay be used to shield signals on these routing traces. Electrode S2 iscoupled with processing system 110 by routing trace 321 and may be heldat a constant voltage potential or modulated by processing system 110.As illustrated, in some embodiments, input device 100 is communicativelycoupled with electronic system 150. In one embodiment, the constantvoltage potential may be the system reference. In other embodiments, theconstant voltage potential may be any substantially constant voltage.

In one embodiment, change in the position of an input object, such asfinger F1, may also change the capacitances C_(Y5X1) or C_(Y5X3).Moreover, another input object, such as finger F2, may be further awayfrom the sensor electrodes than finger F1 and may have no or veryminimal substantially effect on C_(X3F2), C_(X4F2), and C_(X4F2).

In FIG. 3A, Arrows A, represent the location and direction of a frontside-sectional view that is illustrated in FIG. 3B. Additionally, inFIG. 3A, circle F1 represents the interaction area of a finger, F1, thatis illustrated in FIG. 3B; while circle F2 represents the interactionare of a finger, F2, that is also illustrated in FIG. 3B.

FIG. 3B shows an exploded side sectional view A-A of a portion of theinput device of FIG. 3A, according to an embodiment. As with FIG. 3A,portions such as substrates, insulators, and routing traces have beenomitted for the purposes of clarity so as not to obscure the depictedportions. In the illustrated embodiment, it can be seen that electrodeS1 is disposed in the same layer as sensor electrodes X, and electrodeS2 is disposed in the same layer as sensor electrodes Y. In otherembodiments, sensor electrodes S1 and S2 may be disposed in the samelayer as one another or in different layers than depicted; for example,electrode S2 may be disposed above routing traces 320 rather than belowas depicted, and sensor electrode S1 may be disposed below routingtraces 310 rather than above as depicted. In addition to section A-A,two input objects 140 in the form of a first finger, F1, and a secondfinger, F2, are shown along with a variety of capacitive couplingswithin and to the sensor electrodes X and Y of sensor electrode pattern200.

With an array of sensing electrodes, such as sensor electrode pattern200, which are arranged in a crossing array where two sets of sensorelectrodes (sensor electrodes X and sensor electrodes Y) are roughlyparallel within the set, the sets may effectively couple together in aset of capacitive combinations larger than that within either setseparately (e.g., the electrode sets may be roughly perpendicularbetween them). Consider an example where there are M sensor electrodesin the set of X sensor electrodes and N sensor electrodes in the set ofY electrodes. Where the sets of X and Y sensor electrodes are roughlyorthogonal, in areas where they extend to cover each other there will becapacitances described by transcapacitance between the sets (e.g.,C_(X1Y2) and C_(Y2X1) for a total number of crossings of up to 2*(M*N)).There will also be capacitances described by absolute capacitance up toM+N=P) from each of the electrodes to a chassis ground (e.g., C_(X1X1)or C_(Y2Y2)). Further within the sets there will be capacitancesdescribed by transcapacitance, which are within the parallel sets (e.g.,up to M*(M−1) and N*(N−1) additional capacitances like C_(X1X2) andC_(Y1Y2)).

In general the number of set-to-set transcapacitances, intra-settranscapacitances, and absolute capacitances, will be a matrix of allcapacitances between each of the sets of electrodes (e.g., P²=[M+N]²).There may also be other electrodes comprising relatively stationary (tosystem ground) shields, or modulated electrodes (e.g., guards) which mayminimized uncontrolled capacitive coupling, or others that may interfererandomly or by increasing the required dynamic range of capacitivemeasurement. In various embodiments, the number of capacitances varybased on the sensor electrode pattern, and in various embodiments, thesensor electrode pattern may be configured to provide a predeterminednumber of absolute, set-to-set transcapacitances and/or intra-settranscapacitances. For example, with reference to the sensor electrodepattern shown in FIG. 2B, (N*M)² capacitances may be determined, where Nis the number of sensor electrodes disposed along a first axis (e.g.,along X axis) and M is the number of sensor electrodes disposed along asecond axis (e.g., along Y axis).

The chassis of input device 100 may in turn be coupled to free-spaceand/or to one or more conductive input objects. Those objects may beeffectively AC grounded (to the chassis) either by contact or throughfree-space, or they may be effectively “floating.” Further high(relative to vacuum or air) dielectric objects may also exist and changecapacitive couplings of the array of sensor electrodes in sensorelectrode pattern 200. For example, the sensitivity of the capacitivemeasurement of the transcapacitances and the cross coupling ofcapacitances may be reduced (shielded) or increased (coupled through thesensor electrode) respectively when the capacitive coupling of thechassis with the input object is high or low respectively. In particularthis may tend to make simple measurements of the capacitances moredifficult in some instances when conventional measurement techniques areemployed.

As previously described, the array of sensor electrodes in sensorelectrode pattern 200 may comprise transmitters and receivers, wheremost generically each of the sensor electrodes may be a transmitter(modulated relative to system ground), a receiver which measures charge(or modulated currents) coupled through the capacitances of transmittersmodulated relative to them (e.g., stationary in voltage relative to thechassis ground), or both (e.g., an absolute capacitance sensitivereceiver modulated relative to ground which measures that capacitanceand also any other relatively modulated electrodes). The sensorelectrodes may also be decoupled from low impedance outputs/inputs suchthat their other couplings dominate and coupling between occur (e.g.,reduced shielding/guarding). The capacitances in sensor electrodepattern 200 may then be estimated by measuring the charge to voltageratio (e.g., measuring charge for a fixed voltage modulation, ormeasuring voltage for a fixed charge modulation). In some embodiments,when the coupling from an input object to system ground is low, thedirect coupling between sensor electrodes can increase (e.g., theintra-set transcapacitance may increase or the increased couplingthrough the input object may be comparable to the reduced directcoupling between sets). In such embodiments, changes to the electricfield due to the input object may be low. This makes conventionalestimations of the capacitances (e.g., C_(X1Y1) and C_(X4Y2)) based onsingle measurements of charge versus voltage inaccurate and in someembodiments, it may be indeterminable. However, by correlating multiplemeasurements, independent estimates of direct coupling capacitances(e.g., similar to those where the input is fully grounded) can be madeand input locations based on those corrected estimates.

For example, combined capacitive sensing can be employed by scanningwhen all electrodes are receivers (e.g., modulating each electrode insequence while receiving on the others) will generate a P*P matrix (ofmeasured capacitance or demodulated charge) where the total number ofelectrodes is P=M+N. In the P*P matrix there are two set-to-setcapacitive images (since each symmetric capacitance is measured twice,e.g., C_(X1Y4) and C_(Y4X1)) so two reports may be generated when all ofthe electrodes are scanned. Such inter-set capacitive images may also bereferred to as transcapacitive images as they are made up oftranscapacitive measurements. There are also two pairs of otherintra-set transcapacitance profiles (M×M and N×N respectively) and twoabsolute capacitance profiles (a vector of M and a vector of N). In thecase where user input coupling to system ground is known, correctionscan be made to the images. However, it is possible for multiple levelsof input coupling to be present (e.g., a “floating” coin and a groundedfinger) simultaneously. This makes the location of the objects and theirintroduction and removal difficult to distinguish with a single,conventional measurement of transcapacitance at each crossover location.However, by correlating various capacitance measurements the degree ofcoupling can be estimated and in various embodiments, it can be locallyestimated.

Note that, when performing combined capacitive sensing, the differentmeasurements of both the same symmetric capacitance (though measured ata different time) or of different types of capacitance (e.g., absolutecapacitance, set-to-set transcapacitance, and intra-settranscapacitance) may be correlated with each other to better interpretthe input signals (e.g., even when they are changing or when the groundcoupling of the user is low).

With reference to FIGS. 3A and 3B, the charges transferred by thedifferent capacitances (e.g., absolute capacitances such as C_(X1F1),C_(X3F2), C_(X4F2), C_(Y5F1), C_(Y5F2); set-to-set transcapacitancesC_(Y5X1), C_(Y5X2), C_(Y5X3), C_(Y5X4); and intra-set transcapacitancessuch as C_(X1X2), C_(X2X3)) all occur at substantially same time alongwith other capacitances (e.g., C_(F1S1), C_(FG), and C_(F2B)) but thecoupling through input objects can confound the normal (e.g.,well-grounded user input) assumptions about their effect simply ontranscapacitances collected according conventional sensing techniques.This can lead to bad baselines and Low Ground Mass (LGM) effects thatare difficult to disambiguate from moisture or multiple input objectswhen conventional capacitive sensing techniques are employed. However,when using combined capacitive sensing techniques described herein thecoupling of an input object to ground can be determined by either thereduced charge coupling of an object on an absolute profile measurementor by the increased charge coupling on a transcapacitance measurement ora combination of both.

FIG. 4 shows a matrix 400 of capacitances associated with the inputdevice illustrated in FIG. 3A, according to an embodiment. The multiplecapacitances illustrated in matrix 400 may be acquired via techniques ofcombined capacitive sensing, in some embodiments. For example, absolutecapacitances such as C_(X1X1) . . . C_(X4Y4) form an X profile; absolutecapacitances such as C_(Y1Y1) . . . C_(Y5Y5) form a Y profile;set-to-set transcapacitances such as C_(X1Y1) form an X to Y capacitiveimage; set-to-set transcapacitances such as C_(Y1X1) form an Y to Xcapacitive image; intra-set transcapacitances such as C_(X1X2) andC_(X2X1) form an X to X transcapacitive profile; intra-settranscapacitances such as C_(Y1Y2) and C_(Y2Y1) form a Y to Ytranscapacitive profile; and other capacitances to the shields, guards,and system ground electrode G, such as C_(F1S1) and C_(FG), round outthe matrix. In various embodiments, a first sensor electrode ismodulated such that its absolute capacitance to ground is measured atthe same time that the transcapacitive coupling between the first sensorelectrode and proximate sensor electrodes is measured. For example,sensor electrode X₁ may be modulated to measure its absolute capacitanceC_(X1F1) and to measure the transcapacitive couplings C_(X1Y1),C_(X1Y5), C_(X1X2) and C_(X1X3).

Indeed, various capacitive changes may be correlated differentlydepending on how well input object(s) is/are coupled to system ground.For example, relatively uncoupled inputs (e.g., from different users)can be separately identified by their intra-set transcapacitivecapacitance matrices. In such an example, a first user may be holdingthe input device while a second user is not; however, other orientationsare also possible. The intra-set transcapacitive capacitance effectsbetween separated electrodes is usually also very small so that even inan unknown startup condition a large intra-set transcapacitance betweenseparated sensor electrodes almost certainly indicates a floatingconductive object (e.g., moisture, a coin, etc.) that might be ignoredand that its effect (e.g., on delta set-to-set transcapacitive) could beignored when it is removed as well. Alternatively, effect may beestimated and the estimate removed from data that is reported to a hostprocessor and/or used to calculate reported user inputs. Note thatscanning speed to reconstruct the relevant capacitances is taken intoaccount through modeling; this is because any motion of an input objectmay change the correlated capacitances unless the motion of the inputobjects is modeled. In some embodiments, interleaved measurements of thecapacitances when scanning may aid in reducing such “motion artifacts.”

When using the techniques of combined capacitive sensing (describedherein) to capture capacitances, the LGM effect can typically be modeledby a set of four capacitances from each input object to the sensor(C_(X1F1), C_(Y1F1), C_(X1Y1), and C_(FG)) at each pixel/capacitivecoupling that the input object covers. Most input objects are wellcoupled together (e.g., humans have ˜150 pF to free space and ˜75 pFseries coupling to each other which easily dominate most othercapacitive couplings to a sensor) so that the capacitance from a fingerto ground (C_(FG)) may often be treated as a single variable mostlyindependent of the number of simultaneous input objects and nearbytranscapacitive pixels/capacitive couplings (e.g., crossovers betweenelectrode sets that are located on a neighboring electrode). Multi-input(e.g., multi-touch) interfaces with an input device are more complex,but these may still be modeled by additional capacitances (e.g.,C_(X4F1), C_(X1F1), C_(Y5F1), C_(Y5F2), C_(X4Y5)). It is useful tomeasure at least one of the intra-set transcapacitances (e.g., C_(X1X4)and C_(Y5Y1)) in addition to the absolute capacitances such that crosscapacitive effects can be detected independently and corrected. Notethat for each user input there are three changes in capacitance whichare of great interest (the delta capacitance from the X electrodes tothe finger, dC_(XF); the delta capacitance from the Y electrodes to thefinger, dC_(YF); and the delta capacitance from a transmitting sensorelectrode to a receiving sensor electrode, dC_(TR)) for each inputcapacitive pixel and one uncontrolled capacitance C_(FG) associated withthe coupling of an input object to the chassis. It should be noted thateach additional input capacitive pixel coupling adds three more of thesecapacitances of interest.

The charge coupling that can be measured (e.g., by a capacitive sensorarray such as sensor electrode pattern 200) includes up to 5 capacitivemeasurements if multiple pixels are covered. Also for a particularsensor design the ratio of C_(XF) and C_(YF) to C_(XY) can be correlatedwith a particular C_(FG) and/or coupling between inputs (e.g., for afully covered capacitive pixel, with a given electrode configurationthere is an expected ratio between dC_(XY), dC_(XF), and dC_(YF) for agiven C_(FG)). Using such correlations between capacitive measurementsimages of C_(YS) and profiles of C_(XF) and C_(YF) can be reconstructed(e.g., errors due to C_(FG) may be estimated and/or corrected for) in away that is roughly independent of C_(FG) (e.g., as if it the input iseffectively grounded), and/or each input object may be classified by itschassis coupling (e.g., as a floating or grounded object). It is oftenpreferred that “un-grounded” objects are ignored (e.g., water droplets,or coins) while even partially grounded objects (e.g., small fingers)are accurately detected even when they are only partially coupled to thechassis of the sensor. Although, in some embodiments, sensor electrode Bmay be modulated to estimate the capacitive coupling between sensorelectrode B and system ground.

One method of detecting each of the capacitances within the full Pmatrix is “one hot” scanning where each of the sensor electrodes ismodulated in sequence while the others are held relatively stationary(such as at ground, or some fixed or commonly modulated voltagepotential). In one implementation the modulated sensor electrodeabsolute/self capacitance (e.g., coupling to the chassis) may besimultaneously measured such that all electrodes are used as receivers.In this way part, or the entire matrix of capacitances may be measuredor scanned independently (although the charge coupling through C_(FG)may require multiple measurements from separate pixels or somecorrelation dependent on sensor design). In various embodiments, eachsensor electrode that is scanned measures one row of array 400 of FIG. 4while each column represents the measurement by a sensor electrode. Bymeasuring the transcapacitance matrix by scanning electrodes in sequencefrom the crossing set of electrodes the reduced charge coupling seenwhen multiple (or long and narrow) objects are placed on a singletransmitting electrode since an orthogonal set of electrodes will onlyoverlap the long object at a single location.

In some embodiments, different sensing schemes other than “one hot”scanning can be done to increase the power in various measurements,reduce interference and/or and increase the acquisition rate. Forincreased signal and interference tolerance each sensor may be modulatedas often as possible, in some embodiments. There are possible dynamicrange issues if the coupling between adjacent or overlapping sensorelectrodes is particularly high, but there are also opportunities toreduce the charge coupled dynamic range. For example, in someembodiments, some sensor electrodes such as sensor electrodes Y may belonger and or wider, and thus these sensor electrodes may have moreC_(G) back coupled ground capacitance, which limits their dynamic range.In such a case, neighboring electrodes (e.g., X₁ and X₃) may not bemeasured when X₂ is modulated relative to them. Similarly, in someembodiments, some sensor electrodes such as sensor electrodes X may beshorter and/or narrower, and may be driven to “guard” the others of thesensor electrodes X that are used for transmitting. In variousembodiments, only a subset of the simultaneous capacitive measurementsmay be acquired by the processing system 110. In such embodiments,processing system 110 may only use those sensor electrodes configured toprovide the least dynamic range. For example measured receiverelectrodes may be narrower or shorter than modulated transmitter orguarding electrodes, and the receiver electrodes may be spaced (due totheir narrowness) at a larger distance to each other. Further, theguarding electrodes may be disposed between the receiver sensorelectrode them to reduce their intra group transcapacitive couplingdynamic range. In some embodiments, some sensor electrodes that transmitcan further reduce the required dynamic range by transitioning fartherthan the other sensor electrodes (e.g., by being driven with a modulatedsignal having greater amplitude but being in phase with) and thussubtracting charge that would otherwise need to be supplied by thereceivers that are coupled with receiver sensor electrodes to maintainthe voltage relative to system ground when the transmitter electrode ismodulated. In other embodiments, coded sequences which minimize dynamicrange while optimizing independence of measurements and sensing SNR maybe used.

Both (or only one) of the sensor electrodes X and the sensor electrodesY can still be measuring absolute capacitance profiles whiletransmitting or receiving. In one embodiment, Y may be the preferredshorter and/or narrower and more widely spaced electrodes with X fillingspace between. For scanning, one or more of the sensor electrodes Y cantransition the opposite direction (e.g., 180 degrees out of phase). Byswinging in opposite direction from the electrodes X, this increases thevoltage difference between the orthogonal sensor electrode sets and thusthe Signal to Noise Ratio (SNR) and interference performance ofset-to-set transcapacitance, as well as the interference performance ofany intra-set transcapacitance measurements within either set. Note, insome embodiments, that if all of the sensor electrodes but the scanningsensor electrode are modulated together they may be measuring absolutecapacitance and guarding all other similarly driven electrodes, whileonly the single scanning electrode may be used to measuretranscapacitance between sensor electrodes. Multiple sensor electrodescan also be driven in coded sequences to improve SNR. Where absolutemeasurements are mixed with the result of other measurements may beinterleaved to reduce the effect of temporal variation.

In one embodiment, all of the sensor electrodes in a sensor electrodearray (e.g., sensor electrode pattern 200) are modulated in phase. Invarious embodiments, the amplitudes may vary between axes for thepreviously mentioned charge subtraction effects to balance the requireddynamic range required of the different chassis couplings of X and Ysensor electrode sets). This allows a measurement of the P absolutecapacitive measurements (mixed with some transcapacitance if they arenot modulated with the same amplitude). This can facilitate detectinginputs at longer distances with lower power for “proximity” and “doze”modes. Then, while almost all of the electrodes are still modulated inphase, a single sensor electrode (or a single sensor electrode on eachaxis) may be modulated in the opposite phase to independently measurethe set-to-set transcapacitive matrix (M*N) and the intra-settranscapacitive capacitive matrix (e.g., M*M or N*N). In one embodiment,neighboring intra-set transcapacitively coupled sensor electrodes mayhave reduced modulation (e.g., stationary voltage relative to systemground) to reduce the required dynamic range. Once all of the sensorelectrodes significantly affected by user input are modulated, thenenough measurements of charge coupling have been made to distinguish andindependently reconstruct grounded, partially grounded, and effectivelyun-grounded conductive (or high dielectric) objects influencing theinput device. These reconstructed images, profiles, and distinguishedinput types may be used to control user input (e.g., on a touch screenuser interface/operating system).

Furthermore, capturing active pen signals (e.g., another transmitteroutside the sensor array) can be done in half the time or with half thebandwidth when both axes of sensor electrodes (e.g., sensor electrodes Xand sensor electrodes Y) are sensing simultaneously since both profilescan be captured simultaneously. If multiple independent measurements ofthese profiles are made then the active input can be furtherdistinguished from the other two types. In this way an additional typeof input can be measured substantially simultaneously.

For low voltage high dynamic range receivers, in some embodiments, a“current conveyor” technique may be used to translate the receivedcharge from a receiving sensor electrode. In order to measureabsolute/self capacitance a sensor electrode is modulated between atleast two voltages. Doing this with a single circuit configuration mayimpose restrictions on the size of the voltage change (e.g., how closeto a particular high or low voltage rail) due to the type of transistor(e.g., n or p channel Field Effect Transistors (FETs)). In oneembodiment, to avoid this issue, two current conveyors optimized fordifferent reference voltages with a sensor electrode switched betweenthem may be used. The current conveyors accumulate charge on at leasttwo capacitors for measuring differential or quadrature capacitances(e.g., two or alternately three or four capacitors may be used). Thisallows for modulating the sensor electrodes near the voltage railswithout significantly changing voltages (and charging internalcapacitances) on internal nodes of a current conveyor more than isnecessary for sensing charge coupled from the sensor electrodes.

Example Processing System

FIG. 5 shows a block diagram of an example processing system 110A,according to an embodiment. Processing system 110A may be utilized withan input device (e.g., in place of processing system 110 as part ofinput device 100), according to various embodiments. Processing system110A may be implemented with one or more Application Specific IntegratedCircuits (ASICSs), one or more Integrated Circuits (ICs), one or morecontrollers, or some combination thereof. In one embodiment, processingsystem 110A is communicatively coupled with a plurality of sensorelectrodes that implement a sensing region 120 of an input device 100.In some embodiments, processing system 110A and the input device 100, ofwhich it is a part, may be disposed in or communicatively coupled withan electronic system 150, such as a display device, computer, or otherelectronic system. Reference will be made to sensor electrode pattern200 of FIG. 2A and to one or more of FIGS. 6A, 6B, 6C and 6D indescribing example operations of processing system 100A.

In one embodiment, processing system 110A includes, among othercomponents: sensor module 510, and determination module 520. Processingsystem 110A and/or components thereof may be coupled with sensorelectrodes of a pattern of sensor electrodes, such as sensor electrodepattern 200 or 210, among others. For example, sensor module 510 iscoupled with one or more sensor electrodes (Y, X) of a sensor electrodepattern (e.g., sensor electrode pattern 200) of input device 100.

Sensor module 510 comprises sensing circuitry that is coupled to sensorelectrodes of a sensor electrode pattern, such as via routing. Sensorcircuitry of sensor module 510 may include logic and, in manyembodiments, the sensor circuitry includes one or more amplifiers andassociated circuitry used for transmitting and receiving signals. Suchan amplifier may be interchangeably referred to as an “amplifier,” a“front-end amplifier,” a “receiver,” an “integrating amplifier,” a“differential amplifier,” “transimpedance amplifier”, or the like, andoperates, in some embodiments, to receive a resulting signal (e.g., theresulting signal may be a current signal) at an input and provide aproportional charge which may be output as an integrated voltage. In oneor more embodiments, the sensor module 510 maintains a low impedanceinput when measuring input current or charge. In some embodiments,sensor module 510 may also operate the same or a different amplifier todrive (or modulate) a transmitter signal onto a sensor electrode. Theresulting signal is from one or more sensor electrodes of a sensorelectrode pattern, such as sensor electrode pattern 200, and compriseseffects that result from a transmitter signal that has been driven ontothe sensor electrode or onto another sensor electrode of the sensorelectrode pattern or effects corresponding to an input object proximatethe sensor electrode pattern to which sensor module 510 is coupled. Insome embodiments, a single amplifier may be coupled with and used toreceive a resulting signal from exclusively from a single sensorelectrode. In such embodiments, there would be at least one amplifierfor each sensor electrode in a sensor electrode pattern from which asignal is received. For example, in some embodiments, a first amplifiermay be coupled with a first sensor electrode while a second amplifier iscoupled with a second sensor electrode, and etc. for the number ofsensor electrodes from which signals are received by sensor module 510.In other embodiments, multiple resulting signals from different sensorelectrodes may be summed by sensor module 510. For example, sensorelectrodes may be coupled to different ones of multiple currentconveyors whose output may summed into a single amplifier. In yet otherembodiments, multiple sensor electrodes may be coupled to a commonamplifier through a multiplexer. The multiplexer may select one sensorelectrode at a time or multiple sensor electrodes at a time. Furthermorea multiplexer may allow for sensor electrodes to be connected todifferent receivers or with different polarities or phases to the samereceiver.

Sensor module 510 operates to interact with the sensor electrodes of asensor electrode pattern, such as sensor electrode pattern 200, that areutilized to generate a sensing region 120. This includes operating oneor more sensor electrodes Y to be silent (e.g., not modulated relativeto other sensor electrodes), to be driven with a transmitter signal, tobe used for transcapacitive sensing (intra-set or set-to-set), and/or tobe used for absolute capacitive sensing. This also includes operatingone or more sensor electrodes X to be silent, to be driven with atransmitter signal, to be used for transcapacitive sensing (intra-set orset-to-set), and/or to be used for absolute capacitive sensing.

During transcapacitive sensing, sensor module 510 operates to drive atransmitter signals on one or more sensor electrodes of a set of sensorelectrodes (e.g., one or more of sensor electrodes Y and/or one or moreof sensor electrodes X). A transmitter signal may be a square wave,trapezoidal wave, sine wave, or some other modulated signal. In a giventime interval, sensor module 510 may drive or not drive a transmittersignal (waveform) on one or more of the plurality of sensor electrodesof the sensor electrodes to which it is coupled. Sensor module 510 mayalso be utilized to couple one or more of the non-driven sensorelectrodes to high impedance, ground, or a constant voltage potential,or a modulated voltage when not driving a transmitter signal on suchsensor electrodes. In some embodiments, when performing transcapacitivesensing, sensor module 510 drives two or more transmitter electrodes ofa sensor electrode pattern at one time. When driving two or more sensorelectrodes of a sensor electrode pattern at once, the transmittersignals may be coded according to a coding scheme. The coded transmittersignals may comprise a varying phase, frequency and/or amplitude. Invarious embodiments, the coding scheme may be at least substantiallyorthogonal. Further, the code(s) used may be altered, such as bylengthening or shortening a code to avoid or resist interference. Insome embodiments, sensor module 510 is configured to drive multiplesensor electrodes transmitter signals, where each of the multiple sensorelectrodes are each driven with a different transmitter signal and wherethe transmitter signals are each coded according to a coding scheme. Insuch embodiments, the sensor electrodes may be simultaneously driven.Sensor module 510 also operates to receive resulting signals, via asecond plurality of sensor electrodes during transcapacitive sensing.During transcapacitive sensing, received resulting signals correspond toand include effects corresponding to the transmitter signal(s)transmitted via sensor electrodes that are driven with transmittersignals. These transmitted transmitter signals may be altered or changedin the resulting signal at the receiver due to presence of an inputobject, stray capacitance, noise, interference, and/or circuitimperfections among other factors, and thus may differ slightly orgreatly from their transmitted versions.

In absolute capacitive sensing, sensor module 510 both drives a sensorelectrode relative to system ground or an input object and uses thatdriven sensor electrode to receive a resulting signal that results fromat least the signal driven on to the sensor electrode. In this manner,during absolute capacitive sensing, sensor module 510 operates to drivea signal on to and receive a signal from one or more of sensorelectrodes Y or X. During absolute capacitive sensing, the driven signalmay be referred to as an absolute capacitive sensing signal, transmittersignal, or modulated signal, and it is driven through a routing tracethat provides a communicative coupling between processing system 110Aand the sensor electrode(s) with which absolute capacitive sensing isbeing conducted. It should be appreciated that the transmitter signaldriven onto a particular sensor electrode for transcapacitive sensingand the transmitter signal driven on to that same particular electrodefor absolute capacitive sensing may be similar or identical.

In combined capacitive sensing, sensor module 510 may operate to drive amodulated transmitter signal on one sensor electrode of a sensorelectrode pattern while receiving resulting signals (which compriseeffects that result from the transmitter signal) on at least one and upto all other sensor electrodes of the sensor electrode pattern, andwhile simultaneously also using the modulated transmitter signal tocharge and then receive resulting signals from the driven sensorelectrode for measuring absolute capacitance with that sensor electrode.That is, sensor module 510 may operate to both drive and receive signalsin a manner that facilitates simultaneous absolute capacitive sensingand transcapacitive sensing. It should be appreciated that, whenperforming combined capacitive sensing, sensor module 510 may drivetransmitter signals on more than one sensor electrode eitherconcurrently or at different times. Further, processing system 110 maybe configured to receive resulting signals corresponding to an absolutecapacitive coupling on more than one sensor electrode eitherconcurrently or at different times. As described earlier, thetransmitter signal may be substantially orthogonal, such that they areorthogonal in time, code, frequency, etc.

Determination module 520 may be implemented as hardware (e.g., hardwarelogic and/or other circuitry) and/or as a combination of hardware andinstructions stored in a non-transitory manner in a computer readablestorage medium.

In embodiments where transcapacitive sensing is performed, determinationmodule 520 operates to compute/determine a measurement of a change in atranscapacitive capacitive coupling between a first and second sensorelectrode during transcapacitive sensing. Determination module 520 thenuses such measurements to determine the positional informationcomprising the position of an input object (if any) with respect tosensing region 120. With reference to FIG. 2A, by way of example, thepositional information can be determined from a capacitive image formedof capacitive couplings/pixels like 290, a capacitive profile(transcapacitive or absolute capacitive) formed from capacitivecouplings/pixels like 295, 297, and/or 299, or some combination thereof.With reference to FIG. 2B, the position information can be determinedfrom a capacitive image or profile formed of capacitive couplings/pixelslike 280, 281, 282, 283, and/or 284, or some combination thereof. Insome embodiments, multiple capacitive images/profiles may be combined,correlated, and/or compared to determine position information. Thecapacitive image(s)/profile(s) is/are determined by determination module520 based upon resulting signals acquired by sensor module 510. It isappreciated that, when applicable, determination module 520 operates todecode and reassemble coded resulting signals to construct capacitiveimage(s)/profiles(s) from one or more transcapacitive scan of aplurality of sensor electrodes.

In embodiments where absolute capacitive sensing is performed withsensor electrodes Y and/or X, determination module 520 also operates tocompute/determine a measurement of absolute capacitive coupling (alsoreferred to as background capacitance, C_(B)) to a sensor electrodewhich may be used to form a baseline. When an input object is within asensing region, this comprises additionally comprises a measuring ofabsolute capacitance between the driven sensor electrode(s) and theinput object which may change the total absolute capacitance relative tothe baseline. With respect to the techniques described herein,determination module 520 operates to determine an absolute capacitanceof the sensor electrode (e.g., sensor electrode X1) after an absolutecapacitive sensing signal has been driven on the sensor electrode.Determination module 520 operates to construct capacitive profiles froma plurality of absolute capacitance measurements on an axis. Forexample, in an embodiment where absolute capacitances are measured onindividual sensor electrodes X of sensor electrode pattern 200,determination module 520 determines and constructs a first capacitiveprofile from these absolute capacitive measurements. Similarly, in anembodiment where absolute capacitances are measured on individual sensorelectrodes Y of sensor electrode pattern 200, determination module 520determines and constructs a second capacitive profile from theseabsolute capacitive measurements. In various embodiments, peaks in themeasured response or significant changes in curvature of themeasurements relative to a baseline may be used to identify the locationof input objects.

In embodiments where combined capacitive sensing is performed with asensor electrode pattern and produces resulting signals associated withboth absolute capacitive measurements and transcapacitive measurements,determination module 520 operates to determine capacitive images,transcapacitive profiles, and/or absolute capacitive profiles from thereceived resulting signals and can also combine, correlate, and/orcompare images, profiles, and/or individual capacitances determined fromresulting signals in order to determine position information of anyinput objects in a sensing region of the sensor electrode pattern. Insome embodiments, determination module 520 combines, correlates, and/orcompares these various measurements, profiles, and images, to determinepositional information with respect to an input object and/or todetermine instances when low ground mass effect (C_(XF) or C_(YF) issubstantially equal to C_(FG)) may make it seem as if an input object ispresent (e.g., in a capacitive image) but is not (because it does notalso exist a profile). Alternately, in various embodiments, where anobject appears significant in an intra-axis transcapacitive profile, butdoes not appear in the absolute profile, then the object may also beignored and not reported or absorbed into an image baseline (e.g., itmay be a coin or water droplet).

In some embodiments, processing system 110A comprises decision makinglogic which directs one or more portions of processing system 110A, suchas sensor module 510 and/or determination module 520, to operate in aselected one of a plurality of different operating modes based onvarious inputs.

Processing System Operation

Several examples will now be discussed to illustrate, in part, theoperations of processing system 110A. Reference will be made to sensorelectrode pattern 200 of FIG. 2A in the description of these examples.In these, examples and elsewhere herein, it should be appreciated thattwo sets of substantially orthogonal sensor electrodes (e.g., sensorelectrodes X and sensor electrodes Y of sensor electrode pattern 200)are often described. It should be appreciated that the substantiallyorthogonal sets of sensor electrodes may be disposed in entirelydifferent layers from one another in the sensor electrode pattern,partially in the same layer as one another in the sensor electrodepattern, or entirely in the same common layer as one another in thesensor electrode pattern (e.g., a single layer sensor electrodepattern). Further with reference to FIG. 2B, the sensor electrodes maybe disposed in a matrix (regular or irregular) pattern. In such anembodiment, the sensor electrodes may comprise a similar shape and/orsize. Further, the sensor electrode may cover substantially the entiresensing area (e.g., with very small non-overlapping gaps). Routingtraces coupled to the sensor electrodes may be disposed on a commonlayer to sensor electrodes or on a different layer. The sensorelectrodes or grid electrodes between the sensor electrodes maysubstantially shield the routing traces from the effect of user inputs.Further, the routing traces may be comprised of a common material to thesensor electrodes or a different material. Further still, while notillustrated, one or more grid electrodes may be disposed between thesensor electrodes.

Consider an example where sensor electrode X1 of sensor electrodepattern 200 is driven by sensor module 510 with a modulated transmittersignal. In such an embodiment, first resulting signals (used forabsolute capacitive measurement) may be received from sensor electrodeX1 while second, third, fourth, etc. resulting signals (comprisingeffects of the modulated transmitter signal and used for transcapacitivemeasurement) are simultaneously received from one or more other sensorelectrodes (e.g., X2, X3, X4, Y1, Y2, Y3, Y4, and Y5) of the sensorelectrode pattern 200. For example, resulting signals may be receivedsimultaneously on up to all of sensor electrodes X2, X3, X4, Y1, Y2, Y3,Y4, and Y5. In some embodiments, processing system 110A (e.g., sensormodule 510) may drive a guarding signal on a sensor electrode that isproximate the sensor electrode being driven with the transmitter signal;the guarding signal may be in-phase with the transmitter signal. Forexample, if a modulated transmitter signal is driven on sensor electrodeX1, a guarding signal may be driven on sensor electrode X2 at the sameor at different amplitude that the modulated transmitter signal. In sucha case, resulting signals may not be received from the sensor electrodethat is used for guarding. In one specific embodiment, the guardingsignal is in phase with and comprises the same amplitude as thetransmitter signal. Further, in some embodiments, the sensor electrodedriven with the guard signal may be used to measure a capacitance tosystem ground.

Determination module 520 then determines a capacitive coupling (e.g., anabsolute capacitance) between an input object and the first sensorelectrode, e.g., X1, based on the first resulting signals and a changein capacitive coupling between the first and second sensor electrodesbased on the second resulting signals. In an embodiment where the secondsensor electrode is X2 a change in capacitive coupling between sensorelectrode X1 and sensor electrode X2 is determined; if the second sensorelectrode is Y5 the change in capacitive coupling between sensorelectrode X1 and sensor electrode Y5 is determined.

In some embodiments, sensor module 510 drives a modulated signal on onesensor electrode of a sensor electrode pattern and concurrently drives asecond modulated transmitter signal on a second sensor electrode of thesensor electrode pattern. In one such embodiment, the second modulatedsignal may have a phase opposite that of the modulated signal. Forexample, in one embodiment, when sensor module 510 drives a modulatedtransmitter signal on sensor electrode X1 of sensor electrode pattern200, sensor module 510 also drives a second transmitter signal (e.g.,having opposite phase of the transmitter signal) onto sensor electrodeY5. When sensor module 510 receives resulting signals from sensorelectrodes other than those being driven (e.g., sensor electrodes X2,X3, X4, Y2, Y3, Y4, and Y5) the resulting signals comprise effects fromboth the modulated transmitter signal and the second modulatedtransmitter signal. Alternatively, sensor electrodes X₁ and Y₁ may bedriven with signals being based on different codes or frequencies. Invarious embodiments, while sensor electrode Y₅ is modulated relative tosystem ground the one or more other sensor electrodes may not bemodulated relative to system ground. In such embodiments, sensorelectrode Y₅ may be configured to receive a resulting signal that may beused to determine a measure of the change in absolute capacitance ofsensor electrode Y₅ and changes in transcapacitances between sensorelectrode Y₅ and other sensor electrodes. By also driving sensorelectrode X₁ with a transmitter signal having an opposite phase, thechange in transcapacitance between Y₅ and X₁ may be larger than thechange between Y₅ and other sensor electrodes. In some embodiments, thischange may be almost twice as large.

In some embodiments, when a “one hot” technique is employed, after amodulated signal is driven on a first electrode sensor module 510 drivesa second modulated signal on a second and different sensor electrode.For example, if the modulated signal was driven on sensor electrode X1of sensor electrode pattern 200, first resulting signals could bereceived from sensor electrode X1, while second resulting signals arereceived from sensor electrode X2 and third resulting signals arereceived from sensor electrode Y5. At a time after the first modulatedsignal has been driven (e.g., not concurrent with) a second modulatedsignal is driven. The second modulated signal is not driven on sensorelectrode X1, but instead on another of the sensor electrodes (e.g., X2,X3, X4, Y1, Y2, Y3, Y4, or Y5). Resulting signals, used for absolutecapacitive sensing can then be received on the driven sensor electrodewhile simultaneously receiving resulting signals (comprising effects ofthe second modulated signals and used for transcapacitive sensing) fromany one or more of the non-driven sensor electrodes. For example, thesecond modulated signal can be driven on sensor electrode X2 and fourthresulting signals for absolute capacitive sensing can be received fromsensor electrode X2 while simultaneously receiving fifth and sixthresulting signals for transcapacitive sensing from sensor electrodes X1and Y5. Alternatively, in another example, the second modulated signalcan be driven on sensor electrode Y5 and fourth resulting signals forabsolute capacitive sensing can be received from sensor electrode Y5while simultaneously receiving fifth and sixth resulting signals fortranscapacitive sensing from sensor electrodes X1 and X2. Then, based atleast on the first, second, third, fourth, fifth and sixth resultingsignals, determination module 520 determines a first set-to-setcapacitive image along a first axis (e.g., an axis associated with the Xsensor electrodes), a second set-to-set capacitive image along a secondaxis (e.g., an axis associated with the Y sensor electrodes), anabsolute capacitive profile along the first axis, an absolute capacitiveprofile along the second axis, a transcapacitive profile along the firstaxis (e.g., an intra-set transcapacitive profile of the X electrodes),and a transcapacitive profile along the second axis (e.g., an intra-settranscapacitive profile of the Y electrodes).

Referring now to FIGS. 6A-6D, it should be appreciated that FIGS. 6A,6B, 6C, and 6D only illustrate sensor electrodes of sensor electrodepattern 200 and eliminate depiction of insulating layers, substrates,routing traces, and the like to more clearly depict capacitancesmeasured in various embodiments. Additionally, in FIGS. 6A-6D, forconvenience of labeling capacitances, input object 140 is alsorepresented by a legend of F1 for “Finger 1.” It should be appreciatedthat the description and techniques presented with respect to FIGS.6A-6D may similarly be applied to the sensor electrode pattern 210 ofFIG. 2B.

FIG. 6A shows an exploded front side elevation 610 of the example sensorelectrode pattern 200 of FIG. 2A with labeled capacitances, according toan embodiment. In FIG. 6A, in one embodiment, sensor module 510 drivesonly sensor electrode X1 with a modulated transmitter signal. This is anexample of the “one hot” technique that has been previously mentioned.Sensor module 510 receives resulting signals from sensor electrodes X1,X2, X3, X4, and Y5 which respectively allow determination module 520 todetermine capacitances C_(X1) _(—) _(ABS) (a combination of C_(X1F1) andC_(FG)), C_(X1X2), C_(X1X3), C_(X1X4) and C_(X1Y5). This allows thesensor module to determine the measurements substantially independently.Further, C_(X1F1) may be relatively stationary during measurements.C_(X1F1) allows for the coupling C_(X1) to ground of finger freespace tobe determined. Further, while not illustrated, a capacitance couplingexists between sensor electrode X1 and system ground (electrode G inFIG. 3A) and possibly other electrodes not shown, and depending on theirrelative voltage modulation (e.g. grounded or transmitting an oppositepolarity but not guarding X1), they may be included in a measurement ofcharge through X1 and affect measurement of C_(X1) _(—) _(ABS).

FIG. 6B shows an exploded left side elevation 620 of the example sensorelectrode pattern 200 of FIG. 2A with labeled capacitances, according toan embodiment. FIG. 6B continues the example illustrated in FIG. 6A andshows that when sensor electrode X1 is driven with a modulatedtransmitter signal sensor module 510 also receives resulting signalsfrom sensor electrodes Y1, Y2, Y3, and Y4, which respectively allowdetermination module 520 to determine capacitances C_(X1Y1), C_(X1Y2),C_(X1Y3), and C_(X1Y4). Following this one hot technique, other Xelectrodes can be driven in-turn, and resulting signals can be receivedin a similar fashion.

FIG. 6C shows an exploded front side elevation 630 of the example sensorelectrode pattern 200 of FIG. 2A with labeled capacitances, according toan embodiment. In FIG. 6C, in one embodiment, sensor module 510 drivesonly sensor electrode Y5 with a modulated transmitter signal. This is anexample of the “one hot” technique that has been previously mentioned.Sensor module 510 receives resulting signals from sensor electrodes X1,X2, X3, X4, and Y5 which respectively allow determination module 520 todetermine capacitances C_(Y5X1), C_(Y5X2), C_(Y5X3), C_(Y5X4) and C_(Y5)_(—) _(ABS) (a combination of C_(Y5F1) and C_(FG)).

FIG. 6D shows an exploded left side elevation 640 of the example sensorelectrode pattern 200 of FIG. 2A with labeled capacitances, according toan embodiment. FIG. 6D continues the example illustrated in FIG. 6C andshows that when sensor electrode Y5 is driven with a modulatedtransmitter signal sensor module 510 also receives resulting signalsfrom sensor electrodes Y1, Y2, Y3, and Y4, which respectively allowdetermination module 520 to determine capacitances C_(Y5Y1), C_(Y5Y2),C_(Y5Y3), and C_(Y5Y4). Following this one hot technique, other Yelectrodes can be driven in-turn, and resulting signals can be receivedin a similar fashion.

Example Methods of Operation

FIGS. 7A-7G illustrate a flow diagram 700 of various embodiments of amethod of capacitive sensing. Procedures of embodiments of this methodwill be described with reference to elements and/or components of one ormore of FIGS. 1-6D. It is appreciated that in some embodiments, theprocedures may be performed in a different order than described, thatsome of the described procedures may not be performed, and/or that oneor more additional procedures to those described may be performed.Likewise, it is appreciated that some procedures are carried out bycomponents of processing system such as processing system 100A and/orstored instructions implemented by a processing system such asprocessing system 100A.

With reference to FIG. 7A, at procedure 701 of flow diagram 700, in oneembodiment, a modulated signal is driven onto a first sensor electrodeof a sensor electrode pattern. With respect to sensor electrode pattern200, this can comprise driving a modulated transmitter signal onto anyone of the sensor electrodes X or the sensor electrodes Y. For purposesof example, in one embodiment, this comprises processing system 110A(e.g., sensor module 510) driving a modulated transmitter signal ontosensor electrode X1 of sensor electrode pattern 200.

With continued reference to FIG. 7A, at procedure 702 of flow diagram700, in one embodiment, first resulting signals are received from thefirst sensor electrode. Following the example started in procedure 701,if sensor electrode X1 is the first sensor electrode, then resultingsignals are received from sensor electrode X1 by processing system 110A(e.g., by sensor module 510). The resulting signals may be used todetermine a first charge measurement, Qx_(1F1) (or more generally theseries capacitance through C_(X1) _(—) _(ABS)).

With continued reference to FIG. 7A, at procedure 703 of flow diagram700, in one embodiment, second resulting signals are received from asecond sensor electrode of the sensor electrode pattern. The secondresulting signals comprise effects corresponding to the modulatedsignal; and the first resulting signals and the second resulting signalsare simultaneously received. The second resulting signals may be used todetermine a second charge measurement, Q_(X1X2) Following the example of701 and 702, in an embodiment where sensor electrode X1 is driven with amodulated transmitter signal, second resulting signals can be receivedby processing system 110A (e.g., by sensor module 510) from any of theremaining driven sensor electrodes of sensor electrode pattern 200. Forexample, in one embodiment, processing system 110A (e.g., sensor module510) receives second resulting signals from sensor electrode X2. Inanother embodiment, for example, processing system 110A (e.g., sensormodule 510) receives the second resulting signals from sensor electrodeY5. The second resulting signals may be used to determine a third chargemeasurement, Q_(X1Y5).

With continued reference to FIG. 7A, at procedure 704 of flow diagram700, in one embodiment, a capacitive coupling is determined between aninput object and the first sensor electrode based on the first resultingsignals and change in capacitive coupling between the first and secondsensor electrodes based on the second resulting signals. With referenceto the example described in procedure 703, processing system 110A (e.g.,determination module 520) makes the determination of capacitive couplingin the manner previously described herein. For example, this can includeutilizing, combining, correlating, and/or comparing one or more absolutecapacitive profiles, one or more transcapacitive profiles, and one ormore capacitive images which are determined from the resulting signals.For example, capacitance C_(X1F1) may be determined based on Qx_(X1F1)and a first delta voltage and a capacitance C_(X1X2) may be determinedbased on Q_(X1X2) and a second delta voltage. The first delta voltagemay be defined as a first voltage and system ground and the second deltavoltage may be defined as the first voltage and a second voltage, wherethe second voltage may be ground.

With reference to FIG. 7B, as illustrated in procedure 705 of flowdiagram 700, in some embodiments, the method as described in 701-704further comprises driving a guarding signal is on a third sensorelectrode of the sensor electrode pattern. The third sensor electrode isproximate the first sensor electrode and the guarding signal is in-phasewith the modulated signal. In one embodiment, following the examplediscussed in procedures 701 where a modulated transmitter signal isdriven on sensor electrode X1, a guard signal is driven by processingsystem 110A (e.g., sensor module 510) on sensor electrode X2. Sensorelectrode X2 is proximate and immediately adjacent (no sensor electrodesbetween the two) to sensor electrode X1. Additionally, sensor electrodesX1 and X2 are in the set of sensor electrodes X that are oriented alonga common axis with one another. In one embodiment, the guarding signalis the same modulated transmitter signal that is driven on sensorelectrode X1. The guarding signal may be of lesser amplitude, the sameamplitude, or greater amplitude than the modulated transmitter signaldriven on sensor electrode X1. In another example, if the modulatedtransmitter signal were being driven on sensor electrode Y3, a guardingsignal could be driven on one or more of sensor electrodes Y2 and Y4.

With reference to FIG. 7C, as illustrated in procedure 706 of flowdiagram 700, in some embodiments, the method as described in 701-704further comprises driving a second modulated signal on the second sensorelectrode, wherein the second modulated signal has a phase opposite thatof the modulated signal, and wherein the modulated signal and the secondmodulated signal are driven concurrently. In one embodiment, thiscomprises driving the second modulated signal on a sensor electrode thatis oriented along a different axis that the axis of orientation of thefirst sensor electrode. With reference to the example of procedures701-704 where the first sensor electrode is sensor electrode X1, asecond modulated transmitter signal that is 180 degrees out of phase(but otherwise the same) can be driven on sensor electrode Y5 (or anyother sensor electrode Y). The phase difference means that the signal tonoise ratio is increased (e.g., one sensor electrode is being drivenwith a high signal while the other is being driven with a low signal,and there is a difference in potential between the two that increasesSNR). In such an embodiment, the previously discussed receipt of secondresulting signals from the second sensor electrode of the sensorelectrode pattern, now comprises: receiving the second resulting signalsfrom the second sensor electrode of the sensor electrode pattern (e.g.,by sensor module 510), where the second resulting signals compriseeffects corresponding to the modulated signal driven on the first sensorelectrode and the second modulated signal driven on the second sensorelectrode.

With reference to FIG. 7D, as illustrated in procedure 707 of flowdiagram 700, in some embodiments, the method as described in 701-704further comprises driving a second modulated signal onto the secondsensor electrode of the sensor electrode pattern, where the modulatedsignal and the second modulated signal are driven during explicitlydifferent time periods. For example, during the first time period themodulated signal may be driven on sensor electrode X1 as described inprocedures 701-704; and during a second, different time period that doesnot overlap with the first time period, the modulated signal is drivenby processing system 110A onto the second sensor electrode (e.g., ontosensor electrode X2 or sensor electrode Y5 in the previous example). Inother embodiments, two or more modulated signals based on distant (andpossible substantially orthogonal) codes can be driven onto differentcorresponding sensor electrodes. In such embodiments, each electrode maybe decoded separately. In various embodiments, a first coding scheme maybe used for absolute sensing a second and different coding scheme may beused for transcapacitive sensing. For example, Hadadmard codes may beused for absolute sensing while codes based on Linear Shift Registersmay be used for transcapacitive sensing. Another method ofsimultaneously measuring independent capacitive couplings is to usesubstantially orthogonal frequencies such that an electrode (e.g., Y5)may be substantially guarding at one frequency (e.g. for a firstabsolute capacitive measurement by another electrode such as X1), whilesubstantially stationary at another (e.g. for a second transcapacitivemeasurement by another electrode such as Y4), and even substantiallyopposite phase at a third frequency (e.g., for a third transcapacitivemeasurement by another electrode such as X2). Yet another method is tomake independent capacitive measurements at different phases (e.g., 90degrees for orthogonal sine and cosine modulations) such thatmeasurements of absolute and transcapacitance can be madesimultaneously.

With continued reference to FIG. 7D, at procedure 708 of flow diagram700, the method as described in procedures 701-704 and 707 furthercomprises, receiving third resulting signals from the second sensorelectrode. The third resulting signals are received from the secondsensor electrode after being driven with the second modulated signal.Following the ongoing example, in an embodiment where sensor electrodeX2 is the second sensor electrode, sensor module 510 receives the thirdresulting signals from it; and in an embodiment where sensor electrodeY5 is the second sensor electrode, sensor module 510 receives the secondresulting signals from it.

With continued reference to FIG. 7D, at procedure 709 of flow diagram700, the method as described in procedures 701-704, 707, and 708 furthercomprises, receiving fourth resulting signals from the first sensorelectrode. The fourth resulting signals comprise effects correspondingto the second modulated signal, and the third resulting signals and thefourth resulting signals are simultaneously received. Following theongoing example from procedures 701-704, the fourth resulting signalsare received by sensor module 510 from sensor electrode X1.

With continued reference to FIG. 7D, at procedure 710 of flow diagram700, the method as described in procedures 701-704, 707, 708, and 709further comprises, determining a change in capacitive coupling betweenan input object and the second sensor electrode based on the thirdresulting signals and change in capacitive coupling between the firstand second sensor electrodes based on the fourth resulting signals. Inone embodiment, processing system 110A (e.g., determination module 520)makes the determination of capacitive coupling in the manner previouslydescribed herein. For example, this can include utilizing combining,correlating, and/or comparing more than one type of combinedmeasurements of one or more absolute capacitive profiles, one or moretranscapacitive profiles, and one or more capacitive images which aredetermined from the resulting signals. In embodiments where more thantwo voltages are modulated, charges are accumulated on the receiverswhich are a combination of polarized charge on modulated capacitors.However, by balancing multiple measurements, independent capacitiveestimates may be made from a single combination signal.

With reference to FIG. 7E, as illustrated in procedure 711 of flowdiagram 700, in some embodiments, the method as described in 701-704further comprises driving a second modulated signal on a third sensorelectrode of the sensor electrode pattern. The modulated signal and thesecond modulated signal are simultaneously driven, and the modulatedsignal and the second modulated signal are discrete signals based ondifferent ones of a plurality of codes. As with the first modulatedsignal, the second modulated signal is driven by processing system 110A(e.g., by sensor module 510). Consider example described in procedures701-704, where sensor electrode X1 is the first sensor electrode. In oneembodiment while the modulated signal is being driving on sensorelectrode X1, a second modulated signal is driven on a different sensorelectrode, such as sensor electrode X3 or sensor electrode Y2. A varietyof coding schemes for simultaneously driving sensor electrodes are wellknown to those skilled in the arts of transcapacitive sensing, and manysuch coding schemes may be similarly applied to drive the modulatedsignal and the second modulated signal as signals coded differently fromone another.

With continued reference to FIG. 7E, at procedure 712 of flow diagram700, the method as described in procedures 701-704 and 711 furthercomprises, receiving third resulting signals from the third sensorelectrode that has been driven with the second modulated signal.Processing system 110A (e.g., sensor module 510) can receive the thirdresulting signals. Due to two differently coded modulated signals beingdriven simultaneously, the previously described second resulting signalswill further comprise effects corresponding to the second modulatedsignal as well as effects corresponding to the modulated signal.

With reference to FIG. 7F, as illustrated in procedure 713 of flowdiagram 700, in some embodiments, the method as described in 701-704further comprises receiving third resulting signals with a third sensorelectrode of the sensor electrode pattern, where the third resultingsignals are received simultaneously with the first and second resultingsignals. Consider the example described in procedures 701 and 704, inone embodiment, third resulting signals are received from sensorelectrode X3, fourth resulting signals from sensor electrode X4, fifthresulting signals from sensor electrode Y4, sixth resulting signals fromsensor electrode Y3, seventh resulting signals from sensor electrode Y2,and eighth resulting signals from sensor electrode Y1. Each of the thirdthrough eighth resulting signals comprises effects from the modulatedsignal driven on sensor electrode X1. All of these resulting signals canbe utilized by processing system 110A (e.g., by determination module520) to determine the position of an input object with respect to sensorelectrode pattern 200.

With reference to FIG. 7G, as illustrated in procedure 714 of flowdiagram 700, in some embodiments, the method as described in 701-704utilized a sensor electrode pattern that comprises a first plurality ofsensor electrodes disposed along a first axis (e.g., the axis of thelong edge of each sensor electrodes X) and a second plurality of sensorelectrode disposed along a second axis (e.g., the axis of the long edgeof each of the sensor electrodes Y), where the first axis issubstantially orthogonal to the second axis and where the firstplurality of sensor electrodes comprises the first and second sensorelectrodes. In one such embodiment, the method as described inprocedures 701-704 further comprises receiving third resulting signalswith a third sensor electrode of the second plurality of sensorelectrodes, the third resulting signals comprises effects correspondingto the modulated signal and wherein the third resulting signals compriseeffects corresponding to the modulated signal driven onto the firstsensor electrode. Consider an embodiment where the first sensorelectrode is sensor electrode X1 and the second sensor electrode is X2,then in procedure 714, processing system 110A (e.g., sensor module 510)receives third resulting signals from a sensor electrode of the Y sensorelectrodes, such as sensor electrode Y5.

With continued reference to FIG. 7G, at procedure 715 of flow diagram700, the method as described in procedures 701-704 and 714 furthercomprises, driving a second modulated signal onto the third sensorelectrode. Following the above example, where sensor electrode Y5 is thethird sensor electrode, in one embodiment, processing system 110A (e.g.,sensor module 510) drives a second modulated transmitter signal onsensor electrode Y5. In one embodiment, this second transmitter signalmay be modulated in the same or similar manner as the transmittersignal. In one embodiment, the second modulated transmitter signaldriven at a different time that does not overlap with the driving of thetransmitter signal.

With continued reference to FIG. 7G, at procedure 716 of flow diagram700, the method as described in procedures 701-704, 714, and 715 furthercomprises, receiving fourth resulting signals with the third sensorelectrode. Following the example where sensor electrode Y5 is the thirdsensor electrode, in one embodiment, processing system 110A (e.g.,sensor module 510) receives fourth resulting signals from sensorelectrode Y5.

With continued reference to FIG. 7G, at procedure 717 of flow diagram700, the method as described in procedures 701-704, 714, 715, and 716further comprises, receiving fifth resulting signals with the firstsensor electrode, the fifth resulting signals comprising effectscorresponding to the second modulated signal. Following the examplewhere sensor electrode Y5 is the third sensor electrode and sensorelectrode X1 is the first sensor electrode, in one embodiment,processing system 110A (e.g., sensor module 510) receives the fifthresulting signals from sensor electrode X1.

With continued reference to FIG. 7G, at procedure 718 of flow diagram700, the method as described in procedures 701-704, 714, 715, 716, and717 further comprises, receiving sixth resulting signals with the secondsensor electrode, the sixth resulting signals comprising effectscorresponding to the second modulated signal. Following the examplewhere sensor electrode Y5 is the third sensor electrode, sensorelectrode X1 is the first sensor electrode, and sensor electrode X2 isthe second sensor electrode, in one embodiment, processing system 110A(e.g., sensor module 510) receives the sixth resulting signals fromsensor electrode X2.

With continued reference to FIG. 7G, at procedure 719 of flow diagram700, the method as described in procedures 701-704, 714, 715, 716, 717,and 718 further comprises, determining a first capacitive image alongthe first axis, a second capacitive image along the second axis, anabsolute capacitive profile along the first axis, an absolute capacitiveprofile along the second axis, a transcapacitive profile along the firstaxis, and a transcapacitive profile along the second axis based on thefirst, second, third, fourth, fifth and sixth resulting signals. It isappreciated that many more modulated signals may be driven using the“one hot” technique (for example) described herein or using othertechniques. Other resulting signals may be received and included in thefirst and second capacitive images, the first and second transcapacitiveprofiles, and the first and second absolute capacitive profiles.

The examples set forth herein were presented in order to best explain,to describe particular applications, and to thereby enable those skilledin the art to make and use embodiments of the described examples.However, those skilled in the art will recognize that the foregoingdescription and examples have been presented for the purposes ofillustration and example only. The description as set forth is notintended to be exhaustive or to limit the embodiments to the preciseform disclosed.

What is claimed is:
 1. A processing system comprising: a sensor modulecomprising sensing circuitry coupled to sensor electrodes of a sensorelectrode pattern, said sensor module configured to: drive a modulatedsignal onto a first sensor electrode of said sensor electrode pattern;receive first resulting signals from said first sensor electrode; andreceive second resulting signals from a second sensor electrode of saidsensor electrode pattern, said second resulting signals comprisingeffects corresponding to said modulated signal, and wherein said firstresulting signals and said second resulting signals are simultaneouslyreceived; and a determination module configured to determine acapacitive coupling between an input object and said first sensorelectrode based on said first resulting signals and a change incapacitive coupling between said first and second sensor electrodesbased on said second resulting signals.
 2. The processing system ofclaim 1, wherein said sensor module is further configured to drive aguarding signal on a third sensor electrode of said sensor electrodepattern, said third sensor electrode proximate said first sensorelectrode, wherein said guarding signal is in-phase with said modulatedsignal.
 3. The processing system of claim 1, wherein said sensor moduleis further configured to drive a second modulated signal on said secondsensor electrode, wherein said second modulated signal has a phaseopposite that of said modulated signal, and wherein said modulatedsignal and said second modulated signal are driven concurrently.
 4. Theprocessing system of claim 3, wherein said second resulting signalcomprises effects corresponding to said modulated signal and said secondmodulated signal.
 5. The processing system of claim 1, wherein saidsensor module is further configured to receive third resulting signalswith a third sensor electrode of said sensor electrode pattern, whereinsaid third resulting signals are received simultaneously with said firstresulting signals and said second resulting signals.
 6. The processingsystem of claim 5, wherein said second sensor electrode is one of afirst plurality of sensor electrodes disposed along a first axis of saidsensor electrode pattern; and wherein said third sensor electrode is oneof a second plurality of sensor electrodes disposed along a second axisof said sensor electrode pattern that is substantially orthogonal tosaid first axis.
 7. The processing system of claim 6, wherein: saidsensor module is further configured to: drive a second modulated signalonto said third sensor electrode; receive fourth resulting signals withsaid third sensor electrode; receive fifth resulting signals with saidfirst sensor electrode and sixth resulting signals with said secondsensor electrode, the fifth resulting signals and the sixth resultingsignals comprises effects corresponding to the second modulated signal;and based on the first, second, third, fourth, fifth and sixth resultingsignals, said determination module is further configured to determine afirst capacitive image along said first axis, a second capacitive imagealong said second axis, an absolute capacitive profile along the firstaxis, an absolute capacitive profile along the second axis, atranscapacitive profile along the first axis, and a transcapacitiveprofile along the second axis.
 8. The processing system of claim 7,wherein said first sensor electrode is one of said first plurality ofsensor electrodes.
 9. The processing system of claim 7, wherein saidfirst sensor electrode is one of said second plurality of sensorelectrodes.
 10. A capacitive sensing input device comprising: aplurality of sensor electrodes disposed in a sensor electrode pattern;and a processing system configured to operate said sensor electrodes toperform simultaneous absolute capacitive sensing and transcapacitivesensing, wherein said processing system is configured to: drive amodulated signal onto a first sensor electrode of said sensor electrodepattern; receive first resulting signals from said first sensorelectrode; receive second resulting signals from a second sensorelectrode of said sensor electrode pattern, said second resultingsignals comprising effects corresponding to said modulated signal, andwherein said first resulting signals and said second resulting signalsare simultaneously received; and determine a capacitive coupling betweenan input object and said first sensor electrode based on said firstresulting signals and a change in capacitive coupling between said firstand second sensor electrodes based on said second resulting signals. 11.The capacitive sensing input device of claim 10, wherein said processingsystem is further configured to receive third resulting signals with athird sensor electrode of said sensor electrode pattern, wherein saidthird resulting signals are received simultaneously with said firstresulting signals and said second resulting signals.
 12. The capacitivesensing input device of claim 11, wherein said second sensor electrodeis one of a first plurality of sensor electrodes disposed along a firstaxis of said sensor electrode pattern; and wherein said third sensorelectrode is one of a second plurality of sensor electrodes disposedalong a second axis of said sensor electrode pattern that issubstantially orthogonal to said first axis.
 13. The capacitive sensinginput device of claim 12, wherein said processing system is furtherconfigured to: drive a second modulated signal onto said third sensorelectrode; receive fourth resulting signals with said third sensorelectrode; receive fifth resulting signals with said first sensorelectrode and sixth resulting signals with said second sensor electrode,the fifth resulting signals and the sixth resulting signals compriseseffects corresponding to the second modulated signal; and based on thefirst, second, third, fourth, fifth and sixth resulting signals,determine a first capacitive image along said first axis, a secondcapacitive image along said second axis, an absolute capacitive profilealong the first axis, an absolute capacitive profile along the secondaxis, a transcapacitive profile along the first axis, and atranscapacitive profile along the second axis.
 14. The capacitivesensing input device of claim 12, wherein said first sensor electrode isone of said first plurality of sensor electrodes.
 15. The capacitivesensing input device of claim 12, wherein said first sensor electrode isone of said second plurality of sensor electrodes.
 16. The capacitivesensing input device of claim 12, wherein said sensor electrode patterncomprises a single-layer sensor electrode pattern, and wherein saidfirst plurality of sensor electrodes and said second plurality of sensorelectrodes are disposed entirely in a common layer with one another. 17.The capacitive sensing input device of claim 12, wherein said firstplurality of sensor electrodes and said second plurality of sensorelectrodes are disposed in a different layers of said sensor electrodepattern.
 18. The capacitive sensing input device of claim 10, whereinsaid processing system is further configured to drive a second modulatedsignal on said second sensor electrode, wherein said second modulatedsignal has a phase opposite that of said modulated signal, and whereinsaid modulated signal and said second modulated signal are drivenconcurrently.
 19. The capacitive sensing input device of claim 18,wherein said second resulting signal comprises effects corresponding tosaid modulated signal and said second modulated signal.
 20. A method ofcapacitive sensing, said method comprising: driving a modulated signalonto a first sensor electrode of a sensor electrode pattern; receivingfirst resulting signals from said first sensor electrode; receivingsecond resulting signals from a second sensor electrode of said sensorelectrode pattern, said second resulting signals comprising effectscorresponding to said modulated signal, and wherein said first resultingsignals and said second resulting signals are simultaneously received;and determining a capacitive coupling between an input object and saidfirst sensor electrode based on said first resulting signals and changein capacitive coupling between said first and second sensor electrodesbased on said second resulting signals.
 21. The method as recited inclaim 20, further comprising: driving a guarding signal on a thirdsensor electrode of said sensor electrode pattern, said third sensorelectrode proximate said first sensor electrode, wherein said guardingsignal is in-phase with said modulated signal.
 22. The method as recitedin claim 20, further comprising: driving a second modulated signal onsaid second sensor electrode, wherein said second modulated signal has aphase opposite that of said modulated signal, and wherein said modulatedsignal and said second modulated signal are driven concurrently.
 23. Themethod as recited in claim 22, wherein said receiving second resultingsignals from a second sensor electrode of said sensor electrode pattern,said second resulting signals comprising effects corresponding to saidmodulated signal, comprises: receiving said second resulting signalsfrom said second sensor electrode of said sensor electrode pattern, saidsecond resulting signals comprising effects corresponding to saidmodulated signal and said second modulated signal.
 24. The method asrecited in claim 20, further comprising: driving a second modulatedsignal onto said second sensor electrode, wherein in said modulatedsignal and said second modulated signal are driven during explicitlydifferent time periods; receiving third resulting signals from saidsecond sensor electrode; receiving fourth resulting signals from saidfirst sensor electrode, said fourth resulting signals comprising effectscorresponding to said second modulated signal, and wherein said thirdresulting signals and said fourth resulting signals are simultaneouslyreceived; and determining a change in capacitive coupling between aninput object and said second sensor electrode based on said thirdresulting signals and change in capacitive coupling between said firstand second sensor electrodes based on said fourth resulting signals. 25.The method as recited in claim 20, further comprising: driving a secondmodulated signal on a third sensor electrode of said sensor electrodepattern, wherein said modulated signal and said second modulated signalare simultaneously driven, and wherein said modulated signal and saidsecond modulated signal are discrete signals based on different ones ofa plurality of codes; and receiving third resulting signals from saidthird sensor electrode, wherein said second resulting signals furthercomprise effects corresponding to said second modulated signal.
 26. Themethod as recited in claim 20, further comprising: receiving thirdresulting signals with a third sensor electrode of said sensor electrodepattern, wherein said third resulting signals are receivedsimultaneously with said first resulting signals and said secondresulting signals.
 27. The method as recited in claim 20, wherein thesensor electrode pattern comprises a first plurality of sensorelectrodes disposed along a first axis and a second plurality of sensorelectrode disposed along a second axis, wherein the first axis issubstantially orthogonal to the second axis and wherein the firstplurality of sensor electrodes comprises the first and second sensorelectrodes, wherein the method further comprising: receiving thirdresulting signals with a third sensor electrode of said second pluralityof sensor electrodes, said third resulting signals comprises effectscorresponding to the modulated signal and wherein said third resultingsignals comprise effects corresponding to the modulated signal; drivinga second modulated signal onto said third sensor electrode; receivingfourth resulting signals with said third sensor electrode; receivingfifth resulting signals with said first sensor electrode, the fifthresulting signals comprising effects corresponding to the secondmodulated signal; receiving sixth resulting signals with said secondsensor electrode, said sixth resulting signals comprising effectscorresponding to the second modulated signal; and determining a firstcapacitive image along said first axis, a second capacitive image alongsaid second axis, an absolute capacitive profile along the first axis,an absolute capacitive profile along the second axis, a transcapacitiveprofile along the first axis, and a transcapacitive profile along thesecond axis based on the first, second, third, fourth, fifth and sixthresulting signals.